Devices for detecting or filtering tumor cells

ABSTRACT

Among others, the present invention provides devices each including a micro-filter, a shutter, a cell counter, a selector, a micro-surgical kit, a timer, and a data processing circuitry, wherein the micro-filter is capable of detecting or filtering circulating tumor cells.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional application of U.S. application Ser.No. 14/072,609, filed on Nov. 5, 2013, which is a divisional applicationof U.S. application Ser. No. 14/115,584, filed on Nov. 4, 2013, which isa U.S. national phase application and claims the benefit under 35 U.S.C.§371 of PCT/US2012/036551, filed on May 4, 2012, which in turn claimspriority to U.S. Application No. 61/482,900, filed on May 5, 2011, thecontents of all of which applications are incorporated herein byreference in their entireties.

BACKGROUND OF THE INVENTION

A tumor is an abnormal growth of body tissue and can be cancerous(malignant) or noncancerous (benign). Tumors, particularly canceroustumors, are a serious threat to human well-being and their detection inearly stage is critical in order to obtain effective treatment or cure.However, it is a huge challenge for conventional tumor detection methodsto detect cancer earlier than symptomatically, or detect cancer atearlier stages of tumor metastasis. For example, conventional methodsfail to identify about 40% of cancer patients who are in need of more orenhanced therapies. It is also important to detect any early signs ofspread in cancer following cancer treatments to assess effectiveness ofthe treatment, as well as if and what follow-up treatment is needed.Conventional cancer detection techniques such as x-ray imaging andnuclear magnetic resonance (NMR) imaging fail to provide reliableinformation to the above critical applications.

Recent research and clinical studies have shown that cancer invasion toa human body may occur very early in tumor development. Early detectionand early systemic therapies will result in a declining death rate fromcancer. Metastasis, initiated by tumor cells transported through thecirculation from the primary tumor to vital distant organs, is known tobe the leading cause of cancer related deaths. The early spread of tumorcells to lymph nodes or bone marrow in peripheral blood is referred toas circulating tumor cells (CTCs or CTC). CTCs may still exist in apatient' peripheral blood even after the removal of the primary tumor.

CTCs are essential for establishing metastasis, and detection of CTCs isan important tool to assess the aggressiveness of a given tumor and itspotential of subsequent growth at distant organs. Specific and sensitivedetection of CTCs can be used to identify the overall cancer developmentor metastasis status, survival possibility, and assessment of thetherapeutic response.

With more and more research on CTCs in recent years, its importance tocancer progression gets highly respected. However, CTCs exist in bloodonly on the order of 1 per billion to 10 billion. Present technique toseparate and identify CTCs, on one hand, is quite labor intensive andexpensive, and on the other hand lack accuracy and reliability. Theprocedure includes density gradient separation, immunomagneticseparation and density gradient immunomagnetic separation, and more hardwork in dealing with the identification of the large volume filteredcells by human.

There is a pressing need to find solutions that can bring enhancedsensitivity, specificity, efficiency, convenience, and speed inearly-stage CTC detection at reduced costs.

SUMMARY OF THE INVENTION

The present invention in general relates to a class of innovativemethods and apparatus for detecting tumor cells, particularlycirculating tumor cells (CTCs), by analyzing a biological subject (e.g.,peripheral blood samples or other body fluids samples of a mammal), thendiagnosing the cancer development or metastasis status thereof. It canalso communicate with CTCs, and modify or correct certain aspects ofCTCs. This invention utilizes novel micro-devices or an apparatus withmicro-devices integrated onto it for carrying out diagnosis atmicroscopic levels, in vivo or in vitro, on the biological subject(e.g., fluidic samples such as blood or lymph) containing cells, (e.g.,white and red blood cells, tumor cells). The apparatus can have multipleand enhanced functionalities due to the integrated micro-devices. Theseapparatus can be made by using state-of-the-art micro-device fabricationtechnologies and novel process flows such as integrated circuitfabrication technologies. Apparatus of this invention containingmultiple micro-devices that can detect multiple parameters of abiological subject to be analyzed. These CTC detection apparatus arecapable of detecting cancer diseases at their early stages with a highdegree of sensitivity, specificity, speed, convenience (e.g., reducedequipment size), or affordability (e.g., reduced costs). Examples ofcancers that can be detected by these apparatus include prostate cancer,lung cancer, colon cancer, breast cancer, brain cancer, cervical cancer,Hodgkin's lymphoma, non-Hodgkin's lymphoma, kidney cancer, leukemia,liver cancer, ovarian cancer, skin cancer, testicular cancer, thyroidcancer, pancreatic cancer, endometrial cancer, esophageal cancer, anduterine cancer.

Key component of the detection equipment is a class of novelmicro-devices and their inventive fabrication process flows which enableit to perform at a much higher level than those of conventional diseasedetection equipment or technologies, due to much improved detectionsensitivity, specificity, and speed. Examples of fabrication techniquesthat can be used to make the micro-devices described herein include butnot limited to mechanical, chemical, chemical mechanical,electro-chemical-mechanical, electro-bio-chemical-mechanical, integratedcircuit and semiconductor manufacturing techniques and processes. For ageneral description of some of the applicable fabrication technologies,see, e.g., R. Zaouk et al., Introduction to Microfabrication Techniques,in Microfluidic Techniques (S. Minteer, ed.), 2006, Humana Press;Microsystem Engineering of Lab-on-a-chip Devices, 1st Ed. (Geschke,Klank & Telleman, eds.), John Wiley & Sons., 2004. Micro-devicefunctionalities would at least include sensing, detecting, measuring,diagnosing, monitoring, and analyzing for disease diagnosis. Multiplemicro-devices can be integrated onto a piece of detection apparatus forfurther enhanced measurement sensitivity, specificity, speed andfunctionalities, with ability to measure the same parameter or a set ofdifferent parameters.

Optional components of the apparatus include components for addressing,controlling, forcing, receiving, amplifying, or storing information fromeach probe. Such components can be, e.g., a central control unit thatincludes a controlling circuitry, an addressing unit, an amplifiercircuitry, a logic processing circuitry, a memory unit, an applicationspecific chip, a signal transmitter, a signal receiver, a sensor, amicro-electro-mechanical device, a multi-functional device, or amicro-instrument to perform surgery, drug delivery, cleaning, or medicalfunction.

Specifically, one aspect of this invention provides apparatus fordetecting CTCs in a biological subject, each comprising a firstmicro-device and a first substrate supporting the first micro-device,wherein the first micro-device contacts a biological entity to beanalyzed and is capable of measuring at the microscopic level anelectrical, magnetic, electromagnetic, thermal, optical, fluorescentemission, radiation, acoustical, biological, chemical,electro-mechanical, electro-chemical, electro-optical, electro-thermal,electro-chemical-mechanical, bio-chemical, bio-mechanical, bio-optical,bio-thermal, bio-physical, bio-electro-mechanical, bio-electro-chemical,bio-electro-optical, bio-electro-thermal, bio-mechanical-optical,bio-mechanical thermal, bio-thermal-optical,bio-electro-chemical-optical, bio-electro-mechanical-optical,bio-electro-thermal-optical, bio-electro-chemical-mechanical, physicalor mechanical property, or a combination thereof, of the biologicsubject. The apparatus can further optionally include a device forreading the data from measuring the property.

In some embodiments, the difference in the measured property between thetested biologic subject and that of a biologic subject free of thedisease (i.e., standard biological subject) or between the cellscontained in the tested biological subject and normal cells isindicative of the possible existences of CTCs in the tested biologicalsubject.

In some other embodiments, the electrical property is surface charge,surface potential, resting potential, electrical current, electricalfield distribution, surface charge distribution, cell electronicproperties, cell surface electronic properties, dynamic changes inelectronic properties, dynamic changes in cell electronic properties,dynamic changes in cell surface electronic properties, dynamic changesin surface electronic properties, electronic properties of cellmembranes, dynamic changes in electronic properties of membrane surface,dynamic changes in electronic properties of cell membranes, electricaldipole, electrical quadruple, oscillation in electrical signal (e.g.,oscillation in ions, pulsing electrical field, pulsing surface charge,pulsing voltage), electrical current, capacitance, three-dimensionalelectrical or charge cloud distribution, electrical properties attelomere of DNA and chromosome, capacitance, or impedance; the thermalproperty is temperature or vibrational frequency; the optical propertyis optical absorption, optical transmission, optical reflection,optical-electrical property, brightness, or fluorescent emission;radiation property is radiation emission, signal triggered byradioactive material, or information probed by radioactive material; thechemical property is pH value, chemical reaction, bio-chemical reaction,bio-electro-chemical reaction, reaction speed, reaction energy, speed ofreaction, oxygen concentration, oxygen consumption rate, ionic strength,catalytic behavior, chemical additives to trigger enhanced signalresponse, bio-chemical additives to trigger enhanced signal response,biological additives to trigger enhanced signal response, chemicals toenhance detection sensitivity, bio-chemicals to enhance detectionsensitivity, biological additives to enhance detection sensitivity, orbonding strength; the physical property is density, shape, volume, orsurface area; the biological property is surface shape, surface area,surface charge, surface biological property, surface chemical property,pH, electrolyte, ionic strength, resistivity, cell concentration, orbiological, electrical, physical or chemical property of solution; theacoustic property is frequency, speed of acoustic waves, acousticfrequency and intensity spectrum distribution, acoustic intensity,acoustical absorption, or acoustical resonance; the mechanical propertyis internal pressure, hardness, flow rate, viscosity, fluid mechanicalproperties, shear strength, elongation strength, fracture stress,adhesion, mechanical resonance frequency, elasticity, plasticity, orcompressibility.

In some other embodiments, each of the apparatus further comprises atleast one or more additional micro-devices. In these embodiments, eachof the micro-devices contained in the apparatus comprises a conductivematerial, an electrically insulating material, or a semiconductormaterial; and each of the micro-devices can comprise the same ordifferent material(s) and can measure the same or different propertiesat the same or different time. These multiple micro-devices can bespaced out, e.g., with a distance of at least 10 angstroms on thesubstrate. The multiple micro-devices integrated in a disease detectionapparatus can sequentially or simultaneously various parameters from abiological entity being detected at macroscopic or microscopic levels.

In some other embodiments, each of the micro-devices has the sizeranging from about 1 angstrom (Å) to about 5 millimeter (e.g., from 5 Åto 1 millimeter).

In some other embodiments, the apparatus comprises one or moreadditional substrates on which the micro-devices are placed. Each of thesubstrates can comprise the same or a different material (e.g., aconductive material or an insulator), can be in the same or a differentshape (e.g., a slab, a tube, or an array), and each substrate can be atwo- or three-dimensional object. They can take the form of cylinder,slabs, or any other desired shapes and configurations, in order tofurther improve their measurement sensitivity, specificity, speed,sample size, and reduce cost and size.

The apparatus of the current invention can further count, record, andanalyze the number or amount of circulating tumor cells in a biologicalobject, and mark the cancer progression based on the informationobtained. The apparatus can further predict the treatment efficacy, theprogression-free survival, and overall survival data.

In terms of detection apparatus to integrate micro-devices, in one noveldetection apparatus design, to increase measurement sensitivity,micro-devices mounted on two slabs separated by a small spacing withsample to be measured between the two said slabs can be used to detectCTCs with improved speed, with micro-devices measuring cells in thesample in parallel. The surface area of the slabs can be maximized inorder to have maximum number of micro-devices placed on the slabs andenhance measurement efficiency and speed. Optionally, multiplemicro-devices integrated on the surface of the slabs can be closelyspaced with their spacing matching that of cells.

In another novel configuration, a detection apparatus integrated withmicro-devices is shaped in the form of a cylinder, with multiplemicro-devices with detection probes integrated or mounted in the intersurfaces of the cylinder and with sample to be measured (such as blood,lymph) flowing through the cylinder.

One of the key novel aspects of this patent application is the designand fabrication process flows of micro-devices and methods of using themicro-devices for contacting and measuring properties, at microscopiclevels and in a three dimensional space, of a biological entity (e.g., asingle cell). The micro-devices have micro-probes arranged in a threedimensional manner with feature sizes as small as a cell and capable oftrapping, sorting, probing, measuring, or modifying biological entities.The probe comprises a flexible supporting structure to extend orcontract the probe to move the biological subject.

Another aspect of this invention relates to methods for fabricating amicro-device. The methods include depositing various materials on asubstrate and, in the interims of depositing every two materials,pattern the materials by a microelectronic technology or process,wherein the micro-device is capable of measuring at the microscopiclevel the electric, magnetic, electromagnetic, thermal, optical,acoustical, biological, chemical, physical, or mechanical property of abiologic material that the micro-device is to contact.

Still another aspect of this invention relates to methods forfabricating a micro-device, which include depositing a first material onthe substrate, pattering the first material by a microelectronictechnology or process to give rise to at least one patterned residualand leaving part of the substrate surface uncovered by the firstmaterial, depositing a second non-conductive material atop the processedfirst material and the substrate, creating an opening in the secondmaterial and exposing part of the patterned residual of the firstmaterial, filling up the opening in the second material with a thirdmaterial. In some embodiments, the microelectronic technology or processis thin film deposition, photolithography, etching, cleaning, diffusion,ion implantation, or chemical mechanical polishing.

Yet in still another aspect, the invention provides methods forfabricating a micro-device, which include the first step of depositing afirst material onto a substrate; the second step of depositing a secondmaterial onto the first material and then patterning the second materialwith a microelectronic technology or process; and repeating the secondstep at least once with a material that can be the same as or differentfrom the first or second material. The materials used in the repeatedsteps can be the same as or different from the first or second material.In some embodiments, at least one of the materials used in fabricatingthe micro-device is a piezoelectric material or a conductive material.In some embodiments, multiple fabricated micro-devices can be coupled,joined, and connected by physical or electrical method to constitute themore advanced devices.

In some embodiments, the apparatus of this invention can be integratedon a single device (e.g., by using a semiconductor processingtechnology) or assembled on a board (e.g., by using a computer packagingtechnology).

In some embodiments, patterning of a material is done by amicroelectronic technology or process (e.g., chemical vapor deposition,physical vapor deposition, or atomic layer deposition to deposit variousmaterials on a substrate as an insulator or conductor; lithography andetch to transfer patterns from design to structure; chemical mechanicalplanarization for planarization or patterning; cleaning for particle orcontaminant removal; thermal spiking or anneal to reduce the crystaldefects; diffusion or ion implantation for doping elements into specificlayers). In some embodiments, patterning is planarization by chemicalmechanical polishing.

In some other embodiments, the methods further include removal of astack of multiple layers of materials by wet etch or plasma etch.

In some embodiments, the micro-device can move in any direction. Forinstance, two micro-devices can move in opposite directions.

In some embodiments, the micro-device thus fabricated is so patternedthat it is capable of trapping, sorting, probing, measuring, ormodifying a biological entity; or that it can piece through the membraneof a cell.

Another novel area of this application is the invention ofmicro-indentation probes and micro-probes for measuring a wide range ofphysical properties (such as mechanical properties) of biologicalentities (e.g., cells). Examples of such physical properties include,but are not limited to, hardness, shear strength, elongation strength,fracture stress, elasticity, stiffness, and properties related to cellmembranes as the membranes may be a critical component in diseasediagnosis.

Still yet another aspect of this invention is the design, fabrication,and integration of the various components in the disease detectionapparatus. These components include, e.g., a sample containment anddelivery unit; a delivery unit to deliver oxygen or desired fluid tomaintain and prolong the life of biological entities in the biologicalsample being tested; a sample pre-treatment (or pre-processing) unit toconcentrate diseased entities (such as diseased cells) in the sample; anarray of sample delivery channels; a central disease detection unitcomprising multiple detection probes, a central control unit comprisinga logic processing unit, a memory unit, a sensor, a signal transmitter,a signal receiver, a micro-electro-mechanical device, a multi-functionaldevice, a micro-instrument to perform surgery, drug delivery, cleaning,or medical function, and an application specific chip; and a wastesample treatment unit in which used sample can be treated, recycled,processed for reuse, or disposed.

Finally, another key novel aspect of the current application is thedesign, integration, and fabrication process flow of micro-devicescapable of making highly sensitive and advanced measurements on veryweak signals in biological systems for detecting CTCs on undercomplicated environment with very weak signal and relatively high noisebackground. Those novel capabilities using the class of micro-devicesdisclosed in this invention for disease detection include, e.g., makingdynamic measurements, real time measurements (such as time of flightmeasurements, and combination of using probe signal and detectingresponse signal), phase lock-in technique to reduce background noise,pre-amplification techniques, noise cancellation methods, and 4-pointprobe techniques to measure very weak signals, and unique and novelprobes to measure various electronic, electromagnetic and magneticproperties of biological samples at the single cell level.

As used herein, the term “or” is meant to include both “and” and “or.”In other words, the term “or” may also be replaced with “and/or.”

As used herein, a singular noun is meant to include its plural meaning.For instance, a micro device can mean either a single micro device ormultiple micro-devices.

As used herein, the term “patterning” means shaping a material into acertain physical form or pattern, including a plane (in which case“patterning” would also mean “planarization.”)

As used herein, the term “a biological subject”, “a biological entity”or “a biological sample” for analysis, detection, test, or diagnosisrefers to the subject to be analyzed by an apparatus of this invention.It can be a fluidic sample containing cells, e.g., a blood or lymphsample drawn from a mammal. It also can be a body fluid or its treatedsolutions, e.g., a human peripheral blood, lymphocyte, bone marrow, ortheir treated solutions. A treated solution as used herein refers to asolution that has been used to treat (e.g., wash, clean, suspense,dialyze, or carry) a biological subject.

As used herein, the term “subject” generally refers to part or whole ofa biological entity (such as a mammal, e.g., a human person).

As used herein, the term “microscopic level” refers to the subject beinganalyzed by the CTC detection apparatus of this invention is of amicroscopic nature and can be a single cell, for example white bloodcells, red blood cells, or tumor cells.

As used herein, a “micro-device” or “micro device” can be any of a widerange of materials, properties, shapes, and degree of complexity andintegration. The term has a general meaning for an application from asingle material to a very complex device comprising multiple materialswith multiple sub units and multiple functions. The complexitycontemplated in the present invention ranges from a very small, singleparticle with a set of desired properties to a fairly complicated,integrated unit with various functional units contained therein. Forexample, a simple micro-device could be a single spherical particle of adiameter as small as 100 angstroms with a desired hardness, a desiredsurface charge, or a desired organic chemistry absorbed onto itssurface. A more complex micro device could be a 1 millimeter device witha sensor, a simple calculator, a memory unit, a logic unit, and a cutterall integrated onto it. In the former case, the particle can be formedvia a fumed or colloidal precipitation process, while the device withvarious components integrated onto it can be fabricated using variousintegrated circuit manufacturing processes.

A micro device used in the present invention can range in size (e.g.,diameter) from on the order of about 1 angstrom to on the order of about5 millimeters. For instance, a micro-device ranging in size from on theorder of about 10 angstroms to on the order of 100 microns can be usedin this invention for targeting biological molecules, entities orcompositions of small sizes such as cell structures. Or, a micro-deviceranging in size from on the order of about one micron to the order ofabout 5 millimeters can be used in the present invention for targetingrelatively large biological matters such as a portion of a human organ.As an example, a simple micro-device defined in the present applicationcan be a single particle of a diameter less than 100 angstroms, withdesired surface properties (e.g., with surface charge or a chemicalcoating) for preferential absorption or adsorption onto a targeted cell.

The present invention further provides an apparatus for detecting adisease in a biological subject, which comprises a sample inlet, apre-processing unit, a probing and detecting unit, a signal processingunit, a measurement result display unit, a disposal processing unit, asystem for delivering the biological subject, a system for distributingthe biological subject, a distribution channel, a re-charging unit, adetection device, a global positioning system, a motion device, a signaltransmitter, a signal receiver, a sensor, a memory storage unit, a logicprocessing unit, an application specific chip, a unit for recycling andreclaiming the biological subject, a micro-electro-mechanical device, amulti-functional device, or a micro-instrument to perform surgery, drugdelivery, cleaning, or medical function.

In some embodiments of the apparatus, the pre-processing unit comprisesa sample filtration unit, a recharging unit, a constant pressuredelivery unit, a sample disturbing unit, or a sample pre-probingdisturbing unit. The pre-charging unit increases the contraction ratioof certain substance of interests (such as cancer cells) and thereforemakes the apparatus more effective and efficient in detecting thetargeted biological subject (such as cancer cells), which isparticularly beneficial for detecting very low level of biologicalsubject of interests (such as cancer or tumor cells, e.g., CTCs whichhave a concentration of one part in 1 billion to 10 billion).

In some embodiments, the filtration unit can filter off unwantedsubstance by physical filtration (e.g., based on the electronic chargeor size of the substance) or separation by chemical (thereby completelyremoving the undesirable substances), bio-chemical, bio-physical,bio-electrical, bio-mechanical, electro-mechanical, electro-chemical,thermal, optical, electrical, magnetic, electro-magnetic,electro-chemical-mechanical, electro-biological, electro-bio-chemical,or biological means.

In some embodiments, the sample filtration unit can include an entrancechannel, a disturbing fluid channel, an accelerating chamber, and aslit. The slit and the interior walls of the entrance channel define twochannels (e.g., a top channel and a bottom channel) wherein thebiological subject can be separated due to the differences in itsproperty (e.g., electric or physical property).

In some embodiments, a disturbing fluid is injected into the channel,either before or after the biological subject passes a probingmicro-device, to aid the traveling or separation of the biologicalsubject inside the channel. A bio-compatible fluid can be injected intothe disturbing fluid channel to separate the biological subject. Forexample, the bio-compatible fluid can be injected from the entrance ofthe disturbing fluid channel and deliver to an opening in the entrancechannel wall. The bio-compatible fluid can be liquid or semi-liquid, andcan include saline, water, plasma, an oxygen-rich liquid, or anycombination thereof.

In some other embodiments, the angle between the entrance channel andthe disturbing fluid channel ranges from about 0° to about 180° (e.g.,from about 30° to about 150°, from about 60° to about 120°, or fromabout 75° to about 105°, or about 90°.

In some other embodiments, the width of each channel can range fromabout 1 nm to about 1 mm (e.g., from about 2 nm to about 0.6 mm or fromabout 10 nm to about 0.2 mm). The channel can be straight, curved, orangled. The interior wall of the channel defines a circular, oval,square, rectangular or polygon space. In some other embodiments, thechannel is a circular carbon nano-tube and has a diameter from about 0.5nm to about 1 micron and a length from about 5.0 nm to about 10 mm.

In some other embodiments, at least one of the channels comprises oneprobing device attached to the channel's sidewall, and the probingdevice is capable of measuring at the microscopic level an electrical,magnetic, electromagnetic, thermal, optical, acoustical, biological,chemical, electro-mechanical, electro-chemical, electro-optical,electro-thermal, electro-chemical-mechanical, bio-chemical,bio-mechanical, bio-optical, bio-thermal, bio-physical,bio-electro-mechanical, bio-electro-chemical, bio-electro-optical,bio-electro-thermal, bio-mechanical-optical, bio-mechanical thermal,bio-thermal-optical, bio-electro-chemical-optical,bio-electro-mechanical-optical, bio-electro-thermal-optical,bio-electro-chemical-mechanical, physical or mechanical property, or acombination thereof, of the biologic material. For example, theelectrical property can be surface charge, surface potential, restingpotential, electrical current, electrical field distribution, surfacecharge distribution, cell electronic properties, cell surface electronicproperties, dynamic changes in electronic properties, dynamic changes incell electronic properties, dynamic changes in cell surface electronicproperties, dynamic changes in surface electronic properties, electronicproperties of cell membranes, dynamic changes in electronic propertiesof membrane surface, dynamic changes in electronic properties of cellmembranes, electrical dipole, electrical quadruple, three-dimensionalelectrical or charge cloud distribution, electrical properties attelomere of DNA and chromosome, capacitance, or impedance; the thermalproperty can be temperature or vibrational frequency; the opticalproperty can be optical absorption, optical transmission, opticalreflection, optical-electrical property, brightness, or fluorescentemission; the radiation property can be radiation emission, signaltriggered by radioactive material, or information probed by radioactivematerial; the chemical property can be pH value, chemical reaction,bio-chemical reaction, bio-electro-chemical reaction, reaction speed,reaction energy, speed of reaction, oxygen concentration, oxygenconsumption rate, ionic strength, catalytic behavior, chemical additivesto trigger enhanced signal response, bio-chemical additives to triggerenhanced signal response, biological additives to trigger enhancedsignal response, chemicals to enhance detection sensitivity,bio-chemicals to enhance detection sensitivity, biological additives toenhance detection sensitivity, or bonding strength; the physicalproperty can be density, shape, volume, or surface area; the biologicalproperty can be surface shape, surface area, surface charge, surfacebiological property, surface chemical property, pH, electrolyte, ionicstrength, resistivity, cell concentration, or biological, electrical,physical or chemical property of solution; the acoustic property can befrequency, speed of acoustic waves, acoustic frequency and intensityspectrum distribution, acoustic intensity, acoustical absorption, oracoustical resonance; the mechanical property can be internal pressure,hardness, flow rate, fluid mechanical properties, viscosity, shearstrength, elongation strength, fracture stress, adhesion, mechanicalresonance frequency, elasticity, plasticity, or compressibility.

In some embodiments, at least one of the channels comprises at least twoprobing devices attached to the channel's sidewalls, and the probingdevices are capable of measuring at the microscopic level electrical,magnetic, electromagnetic, thermal, optical, acoustical, biological,chemical, electro-mechanical, electro-chemical, electro-optical,electro-thermal, electro-chemical-mechanical, bio-chemical,bio-mechanical, bio-optical, bio-thermal, bio-physical,bio-electro-mechanical, bio-electro-chemical, bio-electro-optical,bio-electro-thermal, bio-mechanical-optical, bio-mechanical thermal,bio-thermal-optical, bio-electro-chemical-optical,bio-electro-mechanical-optical, bio-electro-thermal-optical,bio-electro-chemical-mechanical, physical or mechanical property, or acombination thereof, of the biologic subject. The probing devicesmeasure the same or different properties at the same time or differenttimes.

The two or more probing devices can be placed with a desired distancebetween each other (at least 10 angstroms). Examples of the desireddistance include from about 10 nm to about 100 mm, from about 100 nm toabout 10 mm, from about 8 microns to about 200 microns, from about 1 mmto about 10 mm.

In some embodiments, the sample filtration unit can comprise an entrancechannel, a bio-compatible filter, an exit channel, or any combinationthereof. When a biological subject passes through the entrance channeltoward the exit channel, the biological subject of a size larger thanthe filter hole will be blocked against the exit channel, resulting inthe smaller biological subject being flushed out through the exitchannel. A bio-compatible fluid is injected from the exit to carry thebiological subject accumulated around the filter and flush out from thechannel. The biological subject with a large size is then filtered forfurther analysis and detection in the detecting component or unit of theapparatus.

In some embodiments, the sample pre-probing disturbing unit can includeone micro-device with a channel, a slit located inside the channel, andoptionally two plates outside the channel. The two plates can apply asignal, e.g., an electronic voltage, to the biological subject travelingthrough the channel and separates it based on the electronic charge thebiological subject carries. The slit and the interior channels of thechannel define two channels where the separated biological subjectsenter and optionally are detected for its property at the microscopiclevel.

In some embodiments., the sample pre-probing disturbing unit applies tothe biological entity an electric, magnetic, electro-magnetic, thermal,optical, acoustical, biological, chemical, electro-mechanical,electro-chemical, electro-chemical-mechanical, bio-chemical,bio-mechanical, bio-electro-mechanical, bio-electro-chemical,bio-electro-chemical-mechanical, physical mechanical signal, or acombination of the above signals. The signal can be applied, e.g., withthe two plates described above or in other means (depending on thenature of the signal). The signal as applied can be pulsed or constant.

In some embodiments, the recharging unit recharges nutrient or respiringgas (such as oxygen) or fluid to the biological subject. Alternatively,it can also clean up the metabolite of the biological subject. With sucha recharging unit, the life stability of the biological subject in thesample is sustained and its use is extended, thereby giving moreaccurate, stable, consistent, and reliable detecting results. Examplesof nutrient include bio-compatible strong or weak electrolyte, aminoacid, mineral, ions, catalysts, oxygen, oxygen-rich liquid, intravenousdrip, glucose, and protein. Another example of the nutrient is asolution containing nano-particles that can be selectively absorbed bycertain biological subjects (e.g., cells or viruses).

The recharging system can be separate from and outside of the othercomponents of the apparatus. Alternatively, it can also be installedwithin one of the other components, e.g., the probing and detecting unitor the disposal processing unit.

In some other embodiments, the signal processing unit comprises anamplifier (e.g., a lock-in amplifier), an A/D (alternate/direct electriccurrent) converter, a micro-computer, a manipulator, a display, andnetwork connections.

In some instances, the signal processing unit collects more than onesignal (i.e., multiple signals), and the multiple signals can beintegrated to cancel noise out or to enhance the signal to noise ratio.The multiple signals can be signals from multiple locations or frommultiple times.

Biological subjects that can be detected by the apparatus include, e.g.,blood, urine, saliva, tear, sweat, and lymph. The detection results canindicate the possible occurrence or presence of a disease (e.g., one inits early stage) in the biological subject.

As used herein, the term “absorption” typically means a physical bondingbetween the surface and the material attached to it (absorbed onto it,in this case). On the other hand, the word “adsorption” generally meansa stronger, chemical bonding between the two. These properties are veryimportant for the present invention as they can be effectively used fortargeted attachment by desired micro devices for measurement at themicroscopic level.

As used herein, the term “contact” (as in “the first micro-devicecontacts a biologic entity”) is meant to include both “direct” (orphysical) contact and “non-direct” (or indirect or non-physical)contact. When two subjects are in “direct” contact, there is generallyno measurable space or distance between the contact points of these twosubjects; whereas when they are in “indirect” contact, there is ameasurable space or distance between the contact points of these twosubjects.

As used herein, the term “probe” or “probing,” in addition to itsdictionary meaning, could mean applying a signal (e.g., an electrical,acoustic, magnetic or thermal signal) to a subject, thereby stimulatingthe subject and causing it to have some kind of intrinsic response.

As used herein, the term “electric property” refers to surface charge,surface potential, resting potential, electrical current, electricalfield distribution, surface charge distribution, cell electronicproperties, cell surface electronic properties, dynamic changes inelectronic properties, dynamic changes in cell electronic properties,dynamic changes in cell surface electronic properties, dynamic changesin surface electronic properties, electronic properties of cellmembranes, dynamic changes in electronic properties of membrane surface,dynamic changes in electronic properties of cell membranes, electricdipole, electrical quadruple, three-dimensional electrical or chargecloud distribution, electrical properties at telomere of DNA andchromosome, break down voltage, capacitance, and impedance of abiological subject to be analyzed.

As used herein, the term “magnetic property” refers to a diamagnetic,paramagnetic, or ferromagnetic property.

As used herein, the term “electro-magnetic property” refers to aproperty that has both electric and magnetic dimensions.

As used herein, the term “thermal property” refers to temperature,freezing point, melting point, evaporation temperature, glass transitiontemperature, thermal conductivity, or vibrational energy of molecules.

As used herein, the term “optical property” refers to reflection,optical absorption, optical scattering, wave length dependentproperties, color, luster, brilliance, scintillation, or dispersion.

As used herein, the term “radiation property” refers to radiationemission, signal triggered by radioactive material, or informationprobed by radioactive material. The meaning of “radiation property” usedin the context of this application has been extended to how an entitysuch as a biological entity responds to or interacts with a radioactivematerial or a product (such as a positron) generated by a radioactivematerial.

As used herein, the term “acoustical property” refers to thecharacteristics found within a structure that determine the quality ofsound in its relevance to hearing. It can generally be measured by theacoustic absorption coefficient. See, e.g., U.S. Pat. No. 3,915,016, formeans and methods for determining an acoustical property of a material;T. J. Cox et al., Acoustic Absorbers and Diffusers, 2004, Spon Press.

As used herein, the term “biological property” is meant to generallyinclude chemical and physical properties of a biological entity.

As used herein, the term “chemical property” refers to reactivity, pHvalue, ionic strength, or bonding strength within the biological sample.

As used herein, the term “physical property” refers to any measurableproperty the value of which describes a physical system's state at anygiven moment in time. The physical properties of a biological sample mayinclude, but are not limited to absorption, albedo, area, brittleness,boiling point, capacitance, color, concentration, density, dielectric,electric charge, electrical conductivity, capacitance, electricalimpedance, electric field, electric potential, emission, flow rate,fluidity, frequency, inductance, intrinsic impedance, intensity,irradiance, luminance, luster, malleability, magnetic field, magneticflux, mass, melting point, momentum, permeability, permittivity,pressure, radiance, solubility, specific heat, strength, temperature,tension, thermal conductivity, velocity, viscosity, volume, and waveimpedance.

As used herein, the term “mechanical property” refers to strength,hardness, toughness, elasticity, plasticity, brittleness, ductility,shear strength, elongation strength, fracture stress, fluid mechanicalproperties, or adhesion of the biological sample.

As used herein, the term “conductive material” (or its equivalent“electric conductor”) is a material which contains movable electriccharges. A conductive material can be a metal (e.g., aluminum, copper,silver, tungsten, or gold) or non-metallic (e.g., graphite, solutions ofsalts, plasmas, or conductive polymers). In metallic conductors, such ascopper or aluminum, the movable charged particles are electrons (seeelectrical conduction). Positive charges may also be mobile in the formof atoms in a lattice that are missing electrons (known as holes), or inthe form of ions, such as in the electrolyte of a battery.

As used herein, the term “electrically insulating material” (also knownas “insulator” or “dielectric”) refers to a material that resists theflow of electric current. An insulating material has atoms with tightlybonded valence electrons. Examples of electrically insulating materialsinclude glass, silicon dioxide, or organic polymers (e.g., rubber,plastics, or Teflon). As used herein, the term “semiconductor” (alsoknown as “semiconducting material”) refers to a material with electricalconductivity due to electron flow (as opposed to ionic conductivity)intermediate in magnitude between that of a conductor and an insulator.Examples of inorganic semiconductors include silicon-based materials.Examples of organic semiconductors include such aromatic hydrocarbons asthe polycyclic aromatic compounds pentacene, anthracene, and rubrene;and polymeric organic semiconductors such as poly(3-hexylthiophene),poly(p-phenylene vinylene), polyacetylene and its derivatives.Semiconducting materials can be crystalline solids (e.g., silicon),amorphous (e.g., hydrogenated amorphous silicon and mixtures of arsenic,selenium and tellurium in a variety of proportions), or even liquid.

As used herein, the term “biological material” has the same meaning of“bio-material” as understood by a person skilled in the art. Withoutlimiting its meaning, biological materials or biomaterials can generallybe produced either in nature or synthesized in the laboratory using avariety of chemical approaches utilizing organic compounds (e.g., smallorganic molecules or polymers) or inorganic compounds (e.g., metalliccomponents or ceramics). They generally can be used or adapted for amedical application, and thus comprise whole or part of a livingstructure or bio-medical device which performs, augments, or replaces anatural function. Such functions may be benign, like being used for aheart valve, or may be bioactive with a more interactive functionalitysuch as hydroxy-apatite coated hip implants. Bio-materials can also beused every day in dental applications, surgery, and drug delivery. Forinstance, a construct with impregnated pharmaceutical products can beplaced into the body, which permits the prolonged release of a drug overan extended period of time. A bio-material may also be an autograft,allograft, or xenograft which can be used as a transplant material. Allthese materials that have found applications in other medical orbiomedical fields can also be used in the present invention.

As used herein, the term “microelectronic technology or process”generally encompasses the technologies or processes used for fabricatingmicro-electronic and optical-electronic components. Examples includelithography, etching (e.g., wet etching, dry etching, or vapor etching),oxidation, diffusion, implantation, annealing, film deposition,cleaning, direct-writing, polishing, planarization (e.g., by chemicalmechanical polishing), epitaxial growth, metallization, processintegration, simulation, or any combinations thereof. Additionaldescriptions on microelectronic technologies or processes can be foundin, e.g., Jaeger, Introduction to Microelectronic Fabrication, 2^(nd)Ed., Prentice Hall, 2002; Ralph E. Williams, Modern GaAs ProcessingMethods, 2^(nd) Ed., Artech House, 1990; Robert F. Pierret, AdvancedSemiconductor Fundamentals, 2^(nd) Ed., Prentice Hall, 2002; S.Campbell, The Science and Engineering of Microelectronic Fabrication,2^(nd) Ed., Oxford University Press, 2001, the contents of all of whichare incorporated herein by reference in their entireties.

As used herein, the term “carbon nano-tube” generally refers to asallotropes of carbon with a cylindrical nanostructure. See, e.g., CarbonNanotube Science, by P. J. F. Harris, Cambridge University Press, 2009,for more details about carbon nano-tubes.

Through the use of a single micro-device or a combination ofmicro-devices integrated into a CTC detection apparatus, the CTCdetection capabilities can be significantly improved in terms ofsensitivity, specificity, speed, cost, apparatus size, functionalities,multi-tasking, and ease of use, along with reduced invasiveness andside-effects. A large number of micro-device types capable of measuringa wide range of microscopic properties of biological sample for CTCdetection can be integrated and fabricated into a single detectionapparatus using micro-fabrication technologies and novel process flowsdisclosed herein. While for the purposes of demonstration andillustration, a few novel, detailed examples have been shown herein onhow microelectronics or nano-fabrication techniques and associatedprocess flows can be utilized to fabricate highly sensitive,multi-functional, and miniaturized detection devices, the principle andgeneral approaches of employing microelectronics and nano-fabricationtechnologies in the design and fabrication of high performance detectiondevices have been contemplated and taught, which can and should beexpanded to various combination of fabrication processes including butnot limited to thin film deposition, patterning (lithography and etch),planarization (including chemical mechanical polishing), ionimplantation, diffusion, cleaning, various materials, and variousprocess sequences and flows and combinations thereof.

BRIEF DESCRIPTIONS OF THE FIGURES

FIGS. 1a-1c provide a perspective illustration of a CTC detectionapparatus of this invention in which a biological sample placed in it ormoving through it can be tested. FIG. 1b and FIG. 1c illustrate theapparatus which comprises multiple individual detection micro-devices.

FIGS. 2a-2n provide a perspective, cross-sectional illustration of a CTCdetection apparatus of this invention with multiple micro-devices. Abiological sample is placed in the apparatus or moving through it whileone or more microscopic properties of this biological sample aremeasured with the multiple micro-devices. FIG. 2b-2l are perspectiveillustrations of the novel process flow for fabricating themicro-device. FIG. 2m-2n are cross-sectional views of an apparatuscomprising multiple individual micro-devices.

FIG. 3 is a perspective, cross-sectional illustration of a CTC detectionapparatus of this invention with multiple micro-devices of differentdetection probes. A biological sample is placed in the apparatus ormoving through it and one or more microscopic properties of this sampleare measured with the multiple micro-device.

FIG. 4 is a perspective illustration of a CTC detection apparatus ofthis invention. It includes two slabs separated by a narrow spacing witha biological sample to be analyzed placed between the slabs, withmultiple micro-devices placed at the inner surfaces of the slabs tomeasure one or more desired parameters of the sample at microscopiclevels.

FIGS. 5a-5l illustrate a novel process flow for fabricating a CTCdetection apparatus of this invention utilizing microelectronicstechnologies.

FIGS. 6a-6b are a perspective illustration of a CTC detection apparatusfabricated by a method of this invention. The apparatus is capable ofprobing a single cell and measuring its microscopic properties.

FIG. 7 is a perspective, cross-sectional illustration of a CTC detectionapparatus of this invention with multiple micro-devices placed at adesired distance for time of flight measurements with enhancedsensitivity, specificity, and speed, including time dependent or dynamicinformation.

FIGS. 8a-8g are a perspective illustration of a novel set of microscopicprobes, included in a CTC detection apparatus of this invention, fordetecting various electronic or magnetic states, configurations, orother properties of a biological sample (e.g., a cell).

FIG. 9 is a perspective illustration of a novel four-point probe,included in a CTC detection apparatus of this invention, for detectingweak electronic signal in a biological sample (e.g., a cell).

FIGS. 10a-10r illustrate a process flow for fabricating some apparatusof this invention.

FIGS. 11a-11l illustrate a novel process flow for fabricating a class ofmicro-devices capable of measuring physical properties of a biologicalentity (e.g., a cell) such as mechanical properties (e.g., hardness,shear strength, elongation strength, fracture stress) and otherproperties related to cell membrane.

FIGS. 12a-12b illustrate how a micro-device with two micro-probescapable of moving in opposite directions when a force is applied can beutilized to probe properties of a biological entity (e.g., mechanicalproperties of a cell membrane).

FIGS. 13a-13b illustrate a novel time of flight detection arrangementfor CTC detection applications, in which both clock signal generator andsignal detection probes are used, along with schematically recordedclock signal, probe signal (signal detected by probing micro-device),and processed and enhanced signal after signal filtering using phaselock-in processing technique to enhance the detected signal.

FIGS. 14a-14b illustrate yet another time of flight CTC detectionarrangement in which clock signal generators, a probe signal generator,and signal detection probes are used, along with schematically recordedclock signal, detected signal by probing micro-device in response toprobe signal, and processed and enhanced signal after signal filteringusing phase lock-in processing technique to enhance the detected signalshowing detected response signal as a function of time (response signaldelays over time in this case).

FIGS. 15a 1-15 c 2 illustrate another novel time of flight CTC detectionapplication, in which a set of novel micro-filters are utilized todetect biological entities via separation of biological entities bytheir various, specific properties such as size, weight, shape,electrical properties, or surface properties.

FIG. 16 illustrates a fluid delivery system, which is a pretreatmentpart for the CTC detection apparatus, and it delivers a sample orauxiliary material at a desired pressure and speed into a device.

FIGS. 17a-17c illustrate a novel device which can engage in cellularcommunications at the single cell level by simulating cellular signalsand receiving the cell's responses which can be a signal of electric,magnetic, electro-magnetic, thermal, optical, acoustical, biological,chemical, electro-mechanical, electro-chemical,electro-chemical-mechanical, bio-chemical, bio-mechanical,bio-electro-mechanical, bio-electro-chemical,bio-electro-chemical-mechanical, physical, or mechanical property. FIG.17(a) illustrates how the signal is processed and responded in a singlecell.

FIG. 18 illustrates a system block diagram of a CTC detection apparatus,comprising various functional modules.

FIGS. 19a-19l illustrate an apparatus capable of communicating,trapping, sorting, analyzing, treating, or modifying a DNA and measuringthe DNA's various properties.

FIGS. 20a-20c illustrate an apparatus of this invention that can detectthe surface charge on biological subjects and separate them by a slitbased on the charge.

FIGS. 21a-21b illustrate another apparatus of this invention that candetect the optical properties of the biological subject with a set ofoptical sensors.

FIG. 22 illustrates another apparatus of this invention that canseparate biological subjects of different geometric size and detecttheir properties respectively.

FIG. 23 illustrates an apparatus of this invention that can measure theacoustic property of a biological subject.

FIG. 24 illustrates an apparatus of this invention that can measure theinternal pressure of a biological subject.

FIGS. 25a-25c illustrate an apparatus of this invention that hasconcaves between the probe couples, in the bottom or ceiling of thechannel.

FIGS. 26a-26b illustrate another apparatus of this invention that hasconcaves of a different shape from those illustrated in FIG. 25.

FIG. 27 illustrates an apparatus of this invention that has a steppedchannel.

FIG. 28 illustrates an apparatus of this invention that has a set ofthermal meters.

FIG. 29 illustrates an apparatus of this invention that includes acarbon nano-tube as the channel with DNA contained therein.

FIGS. 30a-30f illustrated an integrated apparatus of this invention thatincludes a detecting device and an optical sensor.

FIGS. 31a-31c 2 illustrate an integrated apparatus of this inventionthat includes a detecting device and a logic circuitry.

FIGS. 32a-32c illustrate an apparatus of this invention that includes adetecting device and a filter.

FIG. 33 illustrates how micro-devices of this invention can be used tomeasure a DNA′ geometric factors.

FIG. 34 illustrates a process for fabricating a micro-device of thisinvention with a cover atop the trench to form a channel.

FIG. 35 is a diagram of an apparatus of this invention for detecting adisease in a biological subject.

FIG. 36 shows an example of a sample filtration unit.

FIGS. 37a-37b show another example of a sample filtration unit.

FIG. 38 is a diagram of a pre-processing unit of an apparatus of thisinvention.

FIG. 39 is a diagram of an information processing unit of an apparatusof this invention.

FIG. 40 shows the integration of multiple signals which results incancellation of noise and enhancement of signal to noise ratio.

DETAILED DESCRIPTION OF THE INVENTION

One aspect of the present invention relates to apparatus for detectingCTCs in a biological entity in vivo or in vitro (e.g., human being, anorgan, a tissue, or cells in a culture). Each apparatus comprises abiological fluid delivering system, a pre-processing unit, a re-chargingunit, a probing and detecting device, and a discharging unit. Theapparatus is capable of measuring microscopic properties of a biologicalsample. By the constant pressure fluid delivery system, microscopicbiological subjects can be delivered onto or into the pre-processing ordiagnostic micro-device of the apparatus. Compared to traditionaldetection apparatus or technologies, the apparatus provided by thisinvention are advantageous in providing enhanced detection sensitivity,specificity, functionalities, and speed, with reduced costs and size.The apparatus can further include a biological interface, a probingcontrolling and data analysis circuitry, or a system reclaiming ortreating medical waste. Additional micro-devices, e.g., a seconddetection device, can also be included or integrated into the apparatusfor enhanced detection capabilities.

As a key component of the apparatus, the micro-device should includemeans to perform at least the function of addressing, controlling,forcing, receiving, amplifying, analyzing, modifying, correcting, makingdecisions, or storing information from each probing address. As anexample, such means can be a central control unit that includes acontrolling circuitry, an addressing unit, an amplifier circuitry (suchas a lock-in amplifier), a logic processing circuitry, a memory unit, anapplication specific chip, a signal transmitter, a signal receiver, asensor, a unit for recycling and reclaiming the biological subject, amicro-electro-mechanical device, a multi-functional device, or amicro-instrument to perform surgery, drug delivery, cleaning, or medicalfunction.

In some embodiments, the fluid delivering system comprises a pressuregenerator, a pressure regulator, a throttle valve, a pressure gauge, anddistributing kits. As examples of these embodiments, the pressuregenerator can include a motor piston system and a bin containingcompressed gas; the pressure regulator (which can consist of multipleregulators) can down-regulate or up-regulate the pressure to a desiredvalue; the pressure gauge feeds back the measured value to the throttlevalve which then regulates the pressure to approach the target value.

The biological fluid to be delivered can be a sample of a biologicalentity to be detected for disease or something not necessarily to bedetected for disease. In some embodiments, the fluid to be delivered isliquid (e.g., a blood sample, a urine sample, a saliva sample, a tearsample, a sweat sample, or a lymph sample). The pressure regulator canbe a single pressure regulator or multiple pressure regulators which areplaced in succession to either down-regulate or up-regulate the pressureto a desired level, particularly when the initial pressure is either toohigh or too low for a single regulator to adjust to the desired level ora level that is acceptable for an end device or target.

In some other embodiments, the system controller includes apre-amplifier, a lock-in amplifier, an electrical meter, a thermalmeter, a switching matrix, a system bus, a nonvolatile storage device, arandom access memory, a processor, or a user interface. The interfacecan include a sensor which can be an optical sensor, a voltage meter, acurrent meter, an electrical sensor, a pH meter, a hardness measurementsensor, a thermal sensor, a flow meter, a piezo-meter, or another typeof sensor.

In still some other embodiments, apparatus of this invention furtherinclude a biological interface, a system controller, a system forreclaiming or treatment medical waste. The reclaiming and treatment ofmedical waste can be performed by the same system or two differentsystems.

Another aspect of this invention provides apparatus for interacting witha cell, which include a device for sending a signal to the cell andoptionally receiving a response to the signal from the cell.

In some embodiments, the interaction with the cell can be probing,detecting, sorting, communicating with, treating, or modifying with acoded signal that can be an electric, magnetic, electro-magnetic,thermal, optical, acoustical, biological, chemical, electro-mechanical,electro-chemical, electro-chemical-mechanical, bio-chemical,bio-mechanical, bio-electro-mechanical, bio-electro-chemical,bio-electro-chemical-mechanical, physical, or mechanical signal, or acombination thereof.

In some other embodiments, the device contained in the apparatus caninclude multiple surfaces coated with one or more elements orcombinations of elements, and a control system for releasing theelements. In some instances, the control system can cause release of theelements from the device surface via an energy including but not limitedto thermal energy, optical energy, acoustic energy, electrical energy,electro-magnetic energy, magnetic energy, radiation energy, chemicalenergy, or mechanical energy in a controlled manner. The energy can bein the pulsed form at desired frequencies.

In some other embodiments, the device contained in the apparatusincludes a first component for storing or releasing one element or acombination of elements onto the surface of the cell or into the cell;and a second component for controlling the release of the elements(e.g., a circuitry for controlling the release of the elements). Theelements can be a biological component, a chemical compound, ions,catalysts, Ca, C, Cl, Co, Cu, H, I, Fe, Mg, Mn, N, O, P, F, K, Na, S,Zn, or a combination thereof. The signal, pulsed or constant, can be inthe form of a released element or combination of elements, and it can becarried in a liquid solution, gas, or a combination thereof. In someinstances, the signal can be at a frequency ranging from about 1×10⁴ Hzto about 100 MHz or ranging from about 1×10⁴ Hz to about 10 Hz, or at anoscillation concentration ranging from about 1.0 nmol/L to about 10.0mmol/L. Also, the signal comprises the oscillation of a biologicalcomponent, a chemical compound, Ca, C, Cl, Co, Cu, H, I, Fe, Mg, Mn, N,O, P, F, K, Na, S, Zn, or a combination thereof, e.g., at desiredoscillating frequencies.

In some embodiments, the signal to be sent to the cell can be in theform of oscillating element, compound, or an oscillating density of abiological component, and a response to the signal from the cell is inthe form of oscillating element, compound, or an oscillating density ofa biological component.

In some embodiments, the device can be coated with a biological film,e.g., to enhance compatibility between the device and the cell.

In some other embodiments, the device can include components forgenerating a signal to be sent to the cell, receiving a response to thesignal from the cell, analyzing the response, processing the response,and interfacing between the device and the cell (includingcommunications between the device and the cell), and modifying orcorrecting certain aspects of the cell.

Still another aspect of this invention provides devices each including amicro-filter, a shutter, a cell counter, a selector, a micro-surgicalkit, a timer, and a data processing circuitry. The micro-filter candiscriminate abnormal cells by a physical property (e.g., dimension,shape, or velocity), mechanical property, electric property, magneticproperty, electro-magnetic, thermal property (e.g., temperature),optical property, radiation property, acoustical property, biologicalproperty, chemical property, electro-chemical property, bio-chemicalproperty, bio-physical property, fluid property, bio-electro-chemicalproperty, bio-electro-mechanical property, or electro-mechanicalproperty. In addition, information (such as pressure on the filer, flowrate through the filter, viscosity, temperature change, and adhesionwith the filter), which can be in the form of static and dynamicinformation, can be obtained from interactions between the biologicalentity to be probed and the filter. The devices each can also includeone or more micro-filters. Each of these micro-filters can be integratedwith two cell counters, one of which is installed at the entrance ofeach filter well, while the other is installed at the exit of eachfilter well. The shape of the micro-filter's well is rectangle, ellipse,circular, or polygon; and the micro-filter's dimension ranges from about0.1 μm to about 500 μm or from about 5 μm to about 200 μm. As usedherein, the term “dimension” means the physical or feature size of thefilter opening, e.g., diameter, length, width, or height. The filter canbe coated with a biological or bio-compatible film, e.g., to enhancecompatibility between the device and the cell.

In addition to separation of biological entity by its size and otherphysical features, the filter can also contain additional features andfunctions to perform biological entity separation via other properties,which comprise of mechanical property, electric property, magneticproperty, electro-magnetic, thermal property (e.g., temperature),optical property, radiation property, acoustical property, biologicalproperty, chemical property, electro-chemical property, bio-chemicalproperty, bio-electro-chemical property, bio-electro-mechanicalproperty, and electro-mechanical property.

In some embodiments of these devices, the shutter sandwiched by twofilter membranes can be controlled by a timer (thus time shutter). Thetimer can be triggered by the cell counter. For instance, when a cellpasses through the cell counter of the filter entrance, the clock istriggered to reset the shutter to default position, and moves at apreset speed towards the cell pathway, and the timer records the time asthe cell passes through the cell counter at the exit.

Still a further aspect of this invention provides methods forfabricating a micro-device with micro-trench and probe embedded in themicro-trench's sidewalls. A micro-trench is an unclosed tunnel (see,e.g., FIG. 2(i), 2030), which can be coupled with another upendedsymmetric trench (see, e.g., FIG. 2(k), 2031) to form a closed channel(see, e.g., FIG. 2(l), 2020). The invention can have an array oftrenches. The method may include chemical vapor deposition, physicalvapor deposition, or atomic layer deposition to deposit variousmaterials on a substrate; patterning the deposited layer(s) utilizingmethods comprising of lithography, etch, and chemical mechanicalpolishing to form desired features (such as a trench); chemicalmechanical planarization for surface planarization; chemical cleaningfor particle removal; diffusion or ion implantation for doping elementsinto specific layers; or thermal anneal to reduce the crystal defectsand activate diffused ions. An example of such method includes:depositing a first material onto a substrate; depositing a secondmaterial onto the first material and patterning the second material by amicroelectronic process (e.g., lithography, etch) to form a detectingtip; depositing a third material on the second material and thenplanarize the third material by a polishing process; depositing a fourthmaterial on the third material and patterning the fourth material firstby a microelectronic process (e.g., lithography, etch) and then by amicroelectronic process (e.g., another etch) to remove a portion of thethird material and optionally a portion of the first material while thisetch is typically selective to the second material (lower etch rate forthe second material), in which the fourth material serves as a hardmask.A hardmask generally refers to a material (e.g., inorganic dielectric ormetallic compound) used in semiconductor processing as an etch mask inlieu of polymer or other organic “soft” materials. The probe can have atip alongside the trench. The tip matches spatially with either a majorgroove or a minor groove of DNA. For example, the tip matches spatiallywith interlaced grooves of DNA and the groove interval can be variable.The tip of the probe at the end of trench can also match the end of eachstrand of the DNA helix. The tip's diameter ranges from about 1 angstromto about 10 μm.

In some embodiments, the method further includes coupling two devicesthat are thus fabricated and symmetric (i.e., a flipped mirror) to forma detecting device with channels. The entrance of each channel can beoptionally bell-mouthed, e.g., such that the size of channel's openingend (the entrance) is larger than the channel's body, thereby making iteasier for a cell to enter the channel. The shape of each channel'scross-section can be rectangle, ellipse, circle, or polygon. Themicro-trenches of the coupled two micro-devices can be aligned by themodule of alignment marks designed on the layout of the micro-device.The dimension of the micro-trench can range from about 0.1 μm to about500 μm. The width of the micro-trench ranges from about 0.5 nm to about200 μm (e.g., from about 0.5 nm to about 50 μm), the depth of themicro-trench ranges from about 0.5 nm to about 200 μm (e.g., from about0.5 nm to about 50 μm), and the length of the micro-trench ranges fromabout 1 nm to about 10 mm. The shapes and sizes of different sections ofthe channel can be the same or different.

Alternatively, the method can also include covering the micro-trench ofthe micro-device with a flat panel. Such a panel can comprise or be madewith silicon, SiGe, SiO₂, Al₂O₃, quartz, low optical loss glasses, orother optical materials. Examples of other potentially suitable opticalmaterials include acrylate polymer, AgInSbTe, synthetic alexandrite,arsenic triselenide, arsenic trisulfide, barium fluoride, CR-39, cadmiumselenide, caesium cadmium chloride, calcite, calcium fluoride,chalcogenide glass, gallium phosphide, GeSbTe, germanium, germaniumdioxide, glass code, hydrogen silsesquioxane, Iceland spar, liquidcrystal, lithium fluoride, lumicera, METATOY, magnesium fluoride,agnesium oxide, negative index metamaterials, neutron supermirror,phosphor, picarin, poly(methyl methacrylate), polycarbonate, potassiumbromide, sapphire, scotophor, spectralon, speculum metal, split-ringresonator, strontium fluoride, yttrium aluminium garnet, yttrium lithiumfluoride, yttrium orthovanadate, ZBLAN, zinc selenide, and zinc sulfide.

In other embodiments, the method can further include integrating threeor more micro-devices thus fabricated to yield an enhanced device withan array of the channels.

Another aspect of this invention relates to a set of novel process flowsfor fabricating micro-devices (including micro-probes andmicro-indentation probes) for their applications in CTC detection bymeasuring microscopic properties of a biological sample. Themicro-devices can be integrated into a CTC detection apparatus of thisinvention to measure one or more properties at microscopic levels. Forexample, a cancerous cell may have a different hardness (harder),density (denser), and elasticity than a normal cell.

Another aspect of this invention is to involve in cellularcommunications and regulate cellular decision or response (such asdifferentiation, dedifferentiation, cell division and cell death) withfabricated signals generated by the micro-devices disclosed herein. Thiscould be further employed to detect and treat diseases.

To further enhance measurement capabilities, multiple micro-devices canbe implemented into a piece of detection apparatus employing the time offlight technique, in which at least one probing micro-device and onesensing micro-device placed at a preset, known distance. The probingmicro-device can apply a signal (e.g., a voltage, a charge, anelectrical field, a laser beam, a thermal pulse, a train of ions, or anacoustic wave) to the biological sample to be measured, and thedetection (sensing) micro-device can measure response from or of thebiological sample after the sample has traveled a known distance and adesired period of time. For instance, a probing micro-device can applyan electrical charge to a cell first, and then a detection (sensing)micro-device subsequently measures the surface charge after a desiredperiod of time (T) has lapsed and the cell has traveled a certaindistance (L).

The micro-devices contained in the apparatus of this invention can havea wide range of designs, structures, functionalities, flexibilities, andapplications due to their diverse properties, high degree offlexibilities, and ability of integration, miniaturization, andmanufacturing scalability. They include, e.g., a voltage comparator, afour point probe, a calculator, a logic circuitry, a memory unit, amicro cutter, a micro hammer, a micro shield, a micro dye, a micro pin,a micro knife, a micro needle, a micro thread holder, micro tweezers, amicro laser, a micro optical absorber, a micro mirror, a micro wheeler,a micro filter, a micro chopper, a micro shredder, micro pumps, a microabsorber, a micro signal detector, a micro driller, a micro sucker, amicro tester, a micro container, a signal transmitter, a signalgenerator, a friction sensor, an electrical charge sensor, a temperaturesensor, a hardness detector, an acoustic wave generator, an optical wavegenerator, a heat generator, a micro refrigerator and a chargegenerator.

Further, it should be noted that advancements in manufacturingtechnologies have now made fabrications of a wide range of micro-devicesand integration of various functions onto the same device highlyfeasible and cost effective. The typical human cell size is about 10microns. Using state-of-the-art integrated circuit fabricationtechniques, the minimum feature size defined on a micro-device can be assmall as 0.1 micron or below. Thus, it is ideal to utilize the disclosedmicro-devices for biological applications.

In terms of materials for the micro-devices, the general principle orconsideration is the material's compatibility with a biological entity.Since the time in which a micro-device is in contact with a biologicalsample (e.g., a cell) may vary, depending on its intended application, adifferent material or a different combination of materials may be usedto make the micro-device. In some special cases, the materials maydissolve in a given pH in a controlled manner and thus may be selectedas an appropriate material. Other considerations include cost,simplicity, ease of use and practicality. With the significantadvancements in micro fabrication technologies such as integratedcircuit manufacturing technology, highly integrated devices with minimumfeature size as small as 0.1 micron can now be made cost-effectively andcommercially. One good example is the design and fabrication of microelectro mechanical devices (MEMS), which now are being used in a widevariety of applications in the electronics industry and beyond.

Set forth below are several illustrations or examples of apparatus ofthis invention containing a class of innovative micro-devices that areintegrated into the disease detection apparatus of this invention, andof their fabrication process.

FIG. 1 is a perspective illustration of a CTC detection apparatus ofthis invention 111 in which a biological sample 211 such as a bloodsample placed in it or moving through it is tested. In this figure, anexample of disease detection apparatus 111 is in the form of a cylinder,in which a biological sample 211 flowing through it (from the left sideto the right side in the figure) can be tested for one or moreproperties at the microscopic levels.

To enhance detection speed and sensitivity, a large number ofmicro-devices can be integrated into a single CTC detection apparatus ofthis invention, such as the apparatus illustrated in FIG. 1(b) and FIG.1(c) with the micro-devices spaced to measure a large number of desiredentities (such as cells.) in the biological sample. To achieve the aboverequirements, the detection apparatus should be optimized with itssurface area maximized to contact the biological sample and with largenumber of micro-devices integrated on the maximized surface.

FIG. 2(a) is a perspective, cross-sectional illustration of a CTCdetection apparatus of this invention 122 with multiple identicalmicro-devices 311. A biological sample such as a blood sample 211 placedin it or moving through it can be tested for one or more properties atthe microscopic levels including, e.g., electrical properties (such assurface charge, surface potential, current, impedance, other electricalproperties), magnetic properties, electromagnetic properties, mechanicalproperties (such as density, hardness, shear strength, elongationstrength, fracture tress, and adhesion), biological features, chemicalproperties (e.g., pH or ionic strength), biochemical properties, thermalproperties (e.g., temperature), optical properties, and radiationproperties.

Instead of measuring a single property of a biological entity for CTCdiagnosis, various micro-devices can be integrated into a detectionapparatus to detect multiple properties. FIG. 3 is a perspective,cross-sectional illustration of a CTC detection apparatus of thisinvention 133 with multiple micro-devices 311, 312, 313, 314, and 315,of different detection probes in which a sample 211 such as a bloodsample placed in it or moving through it can be tested for multipleproperties including but not limited to electrical properties (e.g.,surface charge, surface potential, and impedance), magnetic properties,electromagnetic properties, mechanical properties (e.g., density,hardness and adhesion), thermal properties (e.g., temperature),biological properties, chemical properties (e.g., pH), physicalproperties, acoustical properties, optical properties, and radiationproperties.

FIGS. 2(b)-2(n) illustrate a process flow of this invention forfabricating micro-devices for trapping, sorting, probing, measuring, andmodifying biological entities (e.g., a single cell). First, a material2002 (e.g., a non-conducting material) and another material 2003 (e.g.,a conducting material) are sequentially deposited on a substrate 2001(see FIG. 2(b) and FIG. 2(c)). The first material 2003 is thensubsequently patterned by the lithography and etch processes (see FIG.2(d)). Another material 2004 is then deposited (as shown in FIG. 2(e))and planarized (as shown in FIG. 2(f)). Another layer of material 2005is deposited (as shown in FIG. 2(g)) and patterned as a hard mask (asshown in FIG. 2(h)), then followed by etch (as shown in FIG. 2(j)),which is stopped on the substrate 2001. FIG. 2(i) is a perspectiveillustration of the device, while FIG. 2(j) is a vertical illustrationof the device.

As shown in FIG. 2(k), the device 2080 and a mirrored or symmetricdevice 2081 can be coupled together (as shown in FIG. 2.(l)). As such,the apparatus having the pathway with probe embedded in the sidewall isfabricated.

As illustrated in FIG. 2(m) and FIG. 2(n), a large number of detectionmicro-devices can be integrated together to enhance the detectionefficiency.

As illustrated herein, it is desirable to optimize the detectionapparatus design to maximize measurement surface area, since the greaterthe surface area, the greater number of micro-devices that can be placedon the detection apparatus to simultaneously measure the sample, therebyincreasing detection speed and also minimizing the amount of sampleneeded for the test. FIG. 4 is a perspective illustration of a diseasedetection apparatus of this invention 144. It includes two slabsseparated by a narrow spacing with a sample such as a blood sample to bemeasured placed between the slabs, with multiple micro-devices placed atthe inner surfaces of the slabs to measure one or more properties of thesample at microscopic levels.

Yet another aspect of this invention relates to a set of novelfabrication process flows for making micro-devices for CTC detectionpurposes. FIG. 5 illustrates a novel process flow for fabricating a CTCdetection apparatus utilizing microelectronics technologies andprocesses. First, a material 412 is deposited on a substrate 411 (FIG.5(a)). It is then patterned by photolithography and etching processes(FIG. 5(b)). Following the deposition, material 413 is planarized usingchemical mechanical polishing as shown in FIG. 5(d). Recessed areas, inthe form of hole pattern, are next formed in material 413 usingphotolithography and etch processes, as shown in FIG. 5(e), followed bythe deposition of material 414 (FIG. 5(f)). Material 414 above thesurface of material 413 is removed by chemical mechanical polishing(FIG. 5(g), followed by deposition of material 415. Material 415 is nextpatterned using photolithography and etching processes (FIG. 5(i)).Material 414 is next deposited and its excess material above itssubstrate 415 is removed by chemical mechanical polishing (FIGS. 5(j)and (k)). Finally, a light etch or short chemical mechanical polishingto material 415 is carried out to recess material 415, selective tomaterial 414 (FIG. 5(l)), resulting in slight protruding of material414. Material 412 can be a piezoelectric material. When a voltage isapplied to it in the right direction, it will expand and push up,resulting in upward motion in middle tip in material 414. Thus, amicro-device with two probes capable of measuring a range of properties(including mechanical and electrical properties) of biological samplesis fabricated, using the above novel fabrication process flow.

Detection apparatus integrated with micro-devices disclosed in thisapplication is fully capable of detecting pre-chosen properties on asingle cell. FIG. 6 is a perspective illustration of a micro-device 555fabricated by a novel process flow disclosed in this patent application(e.g., novel process flow illustrated in FIG. 5 above) and how such adevice is capable of probing a single cell 666 and measuring the cellfor collecting intended parameters. FIG. 6(a) illustrated a perspective,cross-section of a micro-device 555 with a pair of micro probes 531 and520, where micro probe 531 is in the form of a tip and micro probe 520is in the form of a ring. Both of micro probes 531 and 520 can beconductive and they can serve as a pair of probes to measure electricalproperties of a biological sample. Micro probe 531 is in contact with abase 518 which can be a piezoelectric material. When a voltage isapplied to the base 518 made of a piezoelectric material, the base 518can expand and push micro probe tip 531 upward, which can be useful inmeasuring various properties of a biological sample such as a singlecell. In FIG. 6(b), micro-device 555 is shown to measure a single cell666, using probe tip 531 penetrating through cell membrane 611 and intothe cell's inner space 622, while probe ring 520 making contact withcell membrane 611 at the outside surface of the membrane. This way, themicro-device 555 can make various measurements on the cell, includingits electrical properties (e.g., electrical potential, current acrossthe cell membrane, surface charge on the membrane, and impedance),mechanical properties (e.g., hardness when probe tip 531 is designed asa micro-indentation probe), thermal properties (e.g., temperature),physical properties, and chemical properties (e.g., pH).

In another further aspect, the invention provides the design,integration, and fabrication process flow of micro-devices capable ofmaking highly sensitive and advanced measurements on very weak signalsin biological systems for CTC detection under complicated environmentwith very weak signal and relatively high noise background. Those novelcapabilities using the class of micro-devices disclosed in thisinvention for CTC detection include but not limited to making dynamicmeasurements, real time measurements (such as time of flightmeasurements, and combination of using probe signal and detectingresponse signal), phase lock-in technique to reduce background noise,and 4-point probe techniques to measure very weak signals, and uniqueand novel probes to measure various electronic, electromagnetic andmagnetic properties of biological samples at the single cell (e.g., atelomere of DNA or chromosome).

For example, in a time of flight approach to obtain dynamic informationon the biological sample (e.g., a cell), a first micro-device is firstused to send a signal to perturb the biological entity to be diagnosed,and then a second micro-device is employed to accurately measure theresponse from the biological entity. In one embodiment, the firstmicro-device and the second micro-device are positioned with a desiredor pre-determined distance L apart, with a biological entity to bemeasured flowing from the first micro-device towards the secondmicro-device. When the biological entity passes the first micro-device,the first micro-device sends a signal to the passing biological entity,and then the second micro-device detects the response or retention ofthe perturbation signal on the biological entity. From the distancebetween the two micro-devices, time interval, the nature of perturbationby the first micro-device, and measured changes on the biological entityduring the time of flight, microscopic and dynamic properties of thebiological entity can be obtained. In another embodiment, a firstmicro-device is used to probe the biological entity by applying a signal(e.g., an electronic charge) and the response from the biological entityis detected by a second micro-device as a function of time. The voltageapplied to the biological entity by the micro-device ranges from about0.1 mV to about 10 V, or from about 1 mV to about 1.0 V.

To further increase detection sensitivity, a novel detection process fordisease detection is used, in which time of flight technique isemployed. FIG. 7 is a perspective, cross-sectional illustration ofdetection apparatus 155 with multiple micro-devices 321 and 331 placedat a desired distance 700 for time of flight measurements to attaindynamic information on biological sample 211 (e.g., a cell) withenhanced measurement sensitivity, specificity, and speed. In this timeof flight measurement, one or more properties of the biological sample211 are first measured when the sample 211 passes the first micro-device321. The same properties are then measured again when the sample 211passes the second micro-device 331 after it has travelled the distance700. The change in properties of sample 211 from at micro-device 321 toat micro-device 331 indicates how it reacts with its surroundingenvironment (e.g., a particular biological environment) during thatperiod. It may also reveal information and provide insight on how itsproperties evolve with time. Alternatively, in the arrangement shown inFIG. 7, micro-device 321 could be used first as a probe to apply a probesignal (e.g., an electrical charge) to sample 211 as the sample passesthe micro-device 321. Subsequently, the response of the sample to theprobe signal can be detected by micro-device 331 as the sample passes it(e.g., change in the electrical charge on the sample during the flight).Measurements on biological sample 211 can be done via contact ornon-contact measurements. In one embodiment, an array of micro-devicescan be deployed at a desired spacing to measure properties of thebiological entity over time.

The utilization of micro-devices (e.g., made by using the fabricationprocess flows of this invention) as discussed above and illustrated inFIG. 7 can be helpful for detecting a set of new, microscopic propertiesof a biological sample (e.g., a cell) that have not been considered inexisting detection technologies. Such microscopic properties can beelectric, magnetic, electromagnetic, thermal, optical, acoustical,biological, chemical, electro-mechanical, electro-chemical,electro-chemical-mechanical, bio-chemical, bio-mechanical,bio-electro-mechanical, bio-electro-chemical,bio-electro-chemical-mechanical, physical, or mechanical properties of abiological sample that is a single biological entity (such as a cell).It is known that biological matters includes from basic bonding such asOH, CO, and CH bonding, to complex, three dimensional structures. Someof them have a unique signature in terms of its electronicconfiguration. Some of them may have unique electric, magnetic,electromagnetic, thermal, optical, acoustical, biological, chemical,electro-mechanical, electro-chemical, electro-chemical-mechanical,bio-chemical, bio-mechanical, bio-electro-mechanical,bio-electro-chemical, bio-electro-chemical-mechanical, physical, ormechanical properties and configurations. Normal biological entity anddiseased biological entity may carry different signatures withrespective to the above said properties. However, none of the abovestated parameters or properties have been routinely used as a CTCdetection property. Using a CTC detection apparatus including one ormore micro-devices of this invention, those properties can be detected,measured, and utilized as useful signals for CTC detection, particularlyfor early stage detection of cancer.

FIG. 8 is a perspective illustration of a novel set of microscopicprobes 341, 342, 343, 344, 345, 346, and 347 designed and configured todetect various electronic, magnetic, or electromagnetic states,configurations, or other properties at microscopic level on biologicalsamples 212, 213, 214, and 215, which is a single cell. As an example,in terms of measuring electronic properties, the shapes of biologicalsamples 212, 213, 214, and 215 in FIG. 8 may represent electronicmonopole (sample 212), dipole (samples 213 and 214), and quadruple(sample 215). The micro-devices 341, 342, 343, 344, 345, 346, and 347are optimized to maximize measurement sensitivity of those saidparameters including but not limited to electronic states, electroniccharge, electronic cloud distribution, electrical field, and magneticand electromagnetic properties, and the micro-devices can be designedand arranged in three dimensional configurations. For cancer disease, itis likely that electronic states and corresponding electronic propertiesdiffer between normal and cancerous cells. Therefore, by measuringelectronic, magnetic and electromagnetic properties at microscopiclevels including at cell level, CTC detection sensitivity andspecificity can be improved.

In addition to the above examples in measuring electrical properties(e.g., charge, electronic states, electronic charge, electronic clouddistribution, electrical field, current, and electrical potential, andimpedance), mechanical properties (e.g., hardness, density, shearstrength, and fracture strength) and chemical properties (e.g., pH) in asingle cell, and in FIG. 8 for measuring electrical, magnetic orelectromagnetic states or configurations of biological samples at level,other micro-devices are disclosed in this application for sensitiveelectrical measurements.

FIG. 9 is a perspective illustration of a four-point probe for detectingweak electronic signal in a biological sample such as a cell, where afour point probe 348 is designed to measure electrical properties(impedance, capacitance, and weak electrical current) of a biologicalsample 216.

One of the key aspects of this invention is the design and fabricationprocess flows of micro-devices and methods of use the micro-devices forcatching or measuring biological entities (e.g., cells) at microscopiclevels and in three dimensional space, in which the micro-devices havemicro-probes arranged in three dimensional manner with feature sizes assmall as a cell and capable of trapping, sorting, probing, measuring,detecting, counting, communicating, or modifying biological entities.Such micro-devices can be fabricated using state-of-the-artmicroelectronics processing techniques such as those used in fabricatingintegrated circuits. Using thin film deposition technologies such asmolecular epitaxy beam (MEB) and atomic layer deposition (ALD), filmthickness as thin as a few monolayers can be achieved (e.g., 4 A to 10A). Further, using electron beam or x-ray lithography, device featuresize on the order of nanometers can be obtained, making micro-devicecapable of trapping, probing, measuring, and modifying a biologicalentity (e.g., a single cell) possible.

FIG. 10 illustrates a process flow for fabricating apparatus ormicro-devices of this invention for trapping, sorting, probing,measuring, and modifying biological subjects (e.g., a single cell, a DNAor RNA molecule). In this process flow, microelectronics processes areutilized to fabricate micro-devices designed to achieve the above statedunique functions. Specifically, a first material 712 (typically aconducting material) is first deposited on a substrate 711 (FIG. 10(a)and FIG. 10(b)). The first material 712 is subsequently patterned byusing lithography and etch processes (FIG. 10(c)). A second material 713is then deposited and planarized using chemical mechanical polishingprocess to remove overburden of the second material 713 above the firstmaterial 712 (as shown in FIG. 10(e)). Another layer of material 714 isdeposited and patterned, followed by deposition and planarization bychemical mechanical polishing of another layer of 712 (FIG. 10(f)).Next, a third material 715 is deposited and patterned, using lithographyand etch processes (FIG. 10(g) and FIG. 10(h)), followed by depositionand planarization of a fourth material 716, typically a sacrificialmaterial (FIG. 10(i) and FIG. 10(j)). Repeating the process flow ofdeposition of patterning material 712 or material 715 alternatively, anddeposition of material 716 and planarization by chemical mechanicalpolishing (FIGS. 10(k)-(m)), a film stack featuring multiple layers withalternating material 712 (e.g., a conducting material) and material 715(e.g., an insulating material) in at least portions of the device isformed. Finally, material 716 between film stacks 771 and 772 is removedby wet etch, dry etch (which may require lithography process), or vaporetch, selective to all other materials (FIG. 10(n)). As illustrated inFIG. 10(o), in the case of 712 being a conductive material connected toan electrical circuit or an electrical source (e.g., a charge source),each probe tip formed by 712 on the stack (e.g., 781 and 782) can have acharge or an electrical field at the surface (e.g., 781 and 782), which(each probe tip) can be selected to have a positive charge or a negativecharge, or a positive electrical field or negative electrical field.Conversely, such probe tip can also sense various properties ofbiological subject being measured (e.g., electronic cloud, field,charge, or temperature when the probe tip is a thermal detector, orlight emission when the probe tip is an optical sensor). Usingelectrical circuit or electrical source, various combinations ofelectrical charge distribution or electrical field can be placed on themicro-device, as shown in FIG. 10(o) and FIG. 10(p), which can be usedto sort and trap various biological subjects such as a cell and a DNAmolecule. For instance, a biological subject with a charge distributioninverse of that in FIG. 10(p) can be trapped by the micro-device shownin FIG. 10(p). An array of micro-devices with various chargedistributions or electrical field distributions can trap theirrespective biological subjects in a high speed, which can serve as asorting device. FIGS. 10(q 1) and 10(q 2) illustrate the use of amicro-device capable of trapping a DNA or measuring various properties(e.g., electrical, thermal, or optical properties) of a DNA, with eachprobe tip matched up spatially with either a major groove or minorgroove of a double helix DNA. FIG. 10(r) illustrates how the probe tipsare connected to electrical circuit, where only electrical wiring isshown. It should be noted that the micro-device shown in this examplecan be integrated onto a single chip with one billion or more suchmicro-devices to trap and/or sort cells, DNAs, RNAs, proteins, and otherbiological subject in a high speed.

Another aspect of this invention relates to micro-indentation probes andmicro-probes for measuring a range of physical properties (such asmechanical properties) of biological entities. Examples of themechanical properties include hardness, shear strength, elongationstrength, fracture stress, and other properties related to cell membranewhich is believed to be a critical component in disease diagnosis.

FIG. 11 illustrates a novel fabrication process flow for micro-devicescapable of probing a range of properties of biological entities, such asmechanical properties of cell membrane (e.g., mechanical strength of acell membrane). In this process flow, a material 812 is first depositedonto a substrate 811, followed by the deposition of another material 813(FIG. 11(a)). Following patterning of material 813 using lithography andetch processes, a material 814 is deposited (FIG. 11(b)) and planarized(FIG. 11(c)). Another layer of material 813 is next deposited andpatterned using lithography and etch processes to remove portions of thematerial 813, followed by the deposition and planarization of a material815 (which can be a piezoelectric material and can serve as a driver)(FIG. 11(d)). A layer of material 813 is next deposited, followed bydeposition and patterning of yet another layer of 813, and depositionand planarization of material 816 (FIG. 11(e)). Next, material 816 isetched back to a reduced thickness, and patterned, followed bypatterning of triple-layer of material 813 (FIG. 11(f)). Another layerof 814 is deposited (FIG. 11(g)) and planarized by chemical mechanicalpolishing (FIG. 11(h)), and patterned (FIG. 11(i)). Finally, multiplelayers of 813 are removed by wet etch or vapor etch (FIG. 11(j)). FIG.11(k) is a perspective, cross-sectional illustration of the micro-devicein a plane perpendicular to that in FIG. 11(j) (90-degree rotation fromFIG. 11(j)). FIG. 11(l) illustrates a micro-device with two micro-tips871 and 872 which can move in opposite directions when a voltage isapplied to piezoelectric drivers 881 and 882, which can be used to probebiological entities such as cells.

FIG. 12 is an illustration of how micro-devices fabricated using thenovel manufacturing process shown in FIG. 11 work. In FIG. 12, amicro-device 850 with two micro-probes 866 and 855 can move in oppositedirections upon a force being applied (FIG. 12(a)). When the tips of thetwo probes are penetrated into a cell 870, as the distance between thetwo micro-probes is increased with the increasing applied force, thecell is stretched. Finally, as the applied force is reached a criticalvalue, the cell is broken into two pieces (FIG. 12(b)). The dynamicresponse of the cell to the applied force provides information on thecell, particularly on the mechanical properties (e.g., elasticity) ofcell membrane. The force at the point in which the cell is torn apartreflects the strength of the cell and it may be called a breaking point:the greater the mechanical strength of the cell membrane is, the greaterthe force is at the breaking point.

Another novel approach provided by this invention is the use of phaselock-in measurement for CTC detection, which reduces background noiseand effectively enhances signal to noise ratio. Generally, in thismeasurement approach, a periodic signal is used to probe the biologicalsample and response coherent to the frequency of this periodic probesignal is detected and amplified, while other signals not coherent tothe frequency of the probe signal is filtered out, which therebyeffectively reduces background noise. In one of the embodiments in thisinvention, a probing micro-device can send a periodic probe signal(e.g., a pulsed laser team, a pulsed thermal wave, or an alternatingelectrical field) to a biological entity, response to the probe signalby the biological entity can be detected by a detecting micro-device.The phase lock-in technique can be used to filter out unwanted noise andenhance the response signal which is synchronized to the frequency ofthe probe signal. The following two examples illustrate the novelfeatures of time of flight detection arrangement in combination withphase lock-in detection technique to enhance weak signal and thereforedetection sensitivity in CTC detection measurements.

FIG. 13 is an illustration of a novel time of flight detectionarrangement for CTC detection applications. Specifically, FIG. 13(a)shows a set-up for measuring biological entity 911 using detection probe933 and clock generator 922, and FIG. 13(b) contains recorded signal 921due to structure 922, signal 931 recorded by signal probe 933, andprocessed signal 941 using a phase lock-in technique to filter out noisein recorded signal 931, where only response synchronized to clock signal921 is retained. In the setup shown in FIG. 13(a), when a biologicalentity such as a cell 911 passes a structure 922, it triggers a clearsignal (e.g., a light scattering signal if 922 is a light source, or asharp increase in voltage if 922 is an orifice structure in a resistor).Therefore, 922 can be used to register the arrival of the biologicalsubject, and as a clock when multiple structures of 922 are placed at aperiodic distance as shown in recorded signal trace 921 in FIG. 13(b).In addition, when 922 is placed at a known distance in front of a probe933, it marks the arrival of a biological entity coming towards 933 andsignal response recorded at 933 is delayed by a time t from the signaltriggered by 922 where t equals distance between 922 and 933 divided bytraveling speed of the biological entity. As illustrated in FIG. 13(b),signal 921 due to structure 922 is clear and periodic with periodicityproportional to distance between structure 922s, while signal measuredby probe 933 has a high noise level and relatively weak signal relatedto the biological entity. With the utilization of phase lock-intechnique to filter out noise in recorded signal 931 by the detectionprobe 933 un-synchronized to clock signal 921, signal to noise ratio canbe greatly enhanced as shown in processed signal 941 in FIG. 13(b).

FIG. 14 illustrates yet another time of flight CTC detection arrangementin which a clock signal generator 922, a probe signal generator 944, anda signal detection probe 955 are used, along with schematically recordedclock signal 921, total recorded response signal 951 (except clocksignal), and processed signal 952 using phase lock-in technique. In thisarrangement, a probe signal generator 944 is used to perturb thebiological entity 911 (e.g., heating 911 up using an optical beam, oradding an electrical charge to 911), and response to the probe signal issubsequently measured as a function of time using an array of detectionprobes 955. The filtered signal in 952 shows dynamic response to probesignal by 944 as it decays over time. Since normal cell and abnormalcell may respond differently to the probe signal, this arrangement withproper micro-probes can be utilized to detect cancer. In anotherembodiment utilizing this set-up (shown in FIG. 14), the probe signalgenerator 944 can send a periodic signal to the biological entity 911,detected response signal from the biological entity by the detectionprobe 955 can be processed using the phase lock-in technique, with noiseun-synchronized to the frequency of the probe signal filtered out andsignal synchronized to the probe signal frequency amplified.

FIG. 15 is a perspective illustration of the novel multi-propertymicro-filter. A timed shutter 1502 is sandwiched between 2 pieces offilter membrane 1501 with wells. When a biological subject 1511 movesthrough the pathway of the well, it is first detected by the counter1512, which triggers the clock of the barrier panel 1502. Then thelarger cells will be filtered out, or blocked, by the filter's holes(not in the figure), while only the specific subjects with enough speedare able to get through the pathway 1503 before the timed shutter 1502closes the filter pathway (see FIG. 15(b)). Otherwise it will be heldback as the timed shutter 1502 moves to block the pathway as shown inFIG. 15(c).

FIG. 16 illustrates a fluid delivery system that includes a pressuregenerator, a pressure regulator, a throttle valve, a pressure gauge, anddistributing kits. The pressure generator 1605 sustains fluid withdesired pressure, and the pressure is further regulated by the regulator1601 and then accurately manipulated by the throttle valve 1602.Meanwhile, the pressure is monitored at real time and fed back to thethrottle valve 1602 by the pressure gauge 1603. The regulated fluid isthen in parallel conducted into the multiple devices where a constantpressure is needed to drive the fluid sample.

FIG. 17 illustrates how a micro-device in a CTC detection apparatus ofthis invention can communicate, probe, detect, and optionally treat andmodify biological entities at a microscopic level. FIG. 17(a)illustrates the sequence of cellular events from signal recognition tocell fates determination. First, as the signals 1701 are detected byreceptors 1702 on the cell surface, the cell will integrate and encodethe signals into a biologically comprehensible message, such as calciumoscillation 1703. Consequently, corresponding proteins 1704 in the cellwill interact with the message, then be modified and transform intoion-interacted proteins 1705 accordingly. Through the translocation,these modified proteins 1705 will pass the carried message to thenuclear proteins, and the controlled modification on nuclear proteinswill modulate the expression of gene 1707 which includes transcription,translation, epigenetic processes, and chromatin modifications. Throughmessenger RNA 1709, the message is in turn passed to specific proteins1710, thereby changing their concentration—which then determines orregulates a cell's decision or activities, such as differentiation,division, or even death.

FIG. 17(b) illustrates an apparatus of this invention which is capableof detecting, communicating with, treating, modifying, or probing asingle cell, by a contact or non-contact means. The apparatus isequipped with micro-probes and micro-injectors which are addressed andmodulated by the controlling circuitry 1720. Each individualmicro-injector is supplied with a separate micro-cartridge, whichcarries designed chemicals or compounds.

To illustrate how an apparatus of this invention can be used to simulatean intracellular signal, calcium oscillation is taken as an examplemechanism. First, a Ca²⁺-release-activated channel (CRAC) has to beopened to its maximal extent, which could be achieved by variousapproaches. In an example of the applicable approaches, a biochemicalmaterial (e.g., thapsigargin) stored in the cartridge 1724 is releasedby an injector 1725 to the cell, and the CRAC will open at the stimulusof the biological entity. In another example of the applicableapproaches, the injector 1724 forces a specific voltage on cellmembrane, which causes the CRAC to open as well.

The Ca²⁺ concentration of a solution in the injector 1728 can beregulated as it is a desirable combination of a Ca²⁺-containing solution1726, and a Ca²⁺ free solution 1727. While the injector 1730 contains aCa²⁺ free solution, then injectors 1728 and 1730 are alternatelyswitched on and off at a desired frequency. As such, the Ca²⁺oscillation is achieved and the content inside the cell membrane arethen exposed to a Ca²⁺ oscillation. Consequently, the cell's activitiesor fate is being manipulated by the regulated signal generated by theapparatus.

Meanwhile, the cell's response (e.g., in the form of an electric,magnetic, electromagnetic, thermal, optical, acoustical, or mechanicalproperty) can be monitored and recorded by the probes integrated in thisapparatus.

FIG. 17(c) illustrates another design of apparatus which is able tosetup communication with a single cell. The apparatus is equipped withmicro-probes which are coated with biologically compatible compounds orelements, e.g., Ca, C, Cl, Co, Cu, H, I, Fe, Mg, Mn, N, O, P, F, K, Na,S, or Zn. These probes can generate oscillating chemical signals withsuch an element or compound to interact with the cell, and results intoa response that affects the cell's activities or eventual fate asdescribed above. Likewise, this apparatus can probe and record thecell's response (e.g., in the form of an electric, magnetic,electromagnetic, thermal, optical, acoustical, biological, chemical,electro-mechanical, electro-chemical, electro-chemical-mechanical,bio-chemical, bio-mechanical, bio-electro-mechanical,bio-electro-chemical, bio-electro-chemical-mechanical, physical, ormechanical property) as well.

FIG. 18 illustrates the system block diagram of a CTC detectionapparatus of this invention. This example includes a fluid deliveringsystem 1801, biological interface 1802, a probing and detecting device1803, a system controller 1805, a medical waste reclaiming and treatingsystem 1804. A biological sample or material is transported to theinterface 1802 by the fluid delivery system 1801, meanwhile the fluidparameters (or properties) are reported to the system controller 1805which comprises a logic processing unit, a memory unit, an applicationspecific chip, a sensor, a signal transmitter, and a signal receiver;and then the system controller 1805 can give further command to thesystem. The interface 1802 is an assembly which bridges a fluid sampleand the detecting device, and further monitors the parameters orproperties of the biological sample (e.g., pressure, temperature,stickiness, or flow rate) and then reports the date to the systemcontroller 1805 while distributing the biological sample to the probingand detecting device 1803 with a specified speed or pressure (which canbe commanded by the system controller 1805).

The system controller 1805 is the central commander and monitor of theentire system (or apparatus), where all the parameters and informationfrom various modules is processed and exchanged and the instructions aregiven out, and where the command is dispatched. The system controller1805 can include, e.g., a pre-amplifier, an electrical meter, a thermalmeter, a switching matrix, a system bus, a nonvolatile storage device, arandom access memory, a processor, and a user interface through whichthe user of the apparatus can manipulate, configure the apparatus, andread the operating parameters and final result. The pre-amplifier canprocess the raw signal to a recognizable signal for the meters. Themeters can force and measure corresponding signals which can be, e.g.,electric, magnetic, electromagnetic, thermal, optical, acoustical,biological, chemical, electro-mechanical, electro-chemical,electro-chemical-mechanical, bio-chemical, bio-mechanical,bio-electro-mechanical, bio-electro-chemical,bio-electro-chemical-mechanical, physical, or mechanical signals, orcombinations thereof. The switching matrix can switch the testingterminals of different arrays of the probe sub-apparatus. The userinterface includes input and output assemblies and is an assembly whichseals the fluid delivery system and the probing and detecting devicetogether.

The probing and detecting device 1803 is the core functional module ofthe CTC detection apparatus of this invention as it is the unit thatprobes the biological sample and collects related cellular signals (orresponses). The waste reclaiming and treating system 1804 reclaims thewaste biological sample to protect the privacy of its biological host,and keeps it away from polluting the environment.

FIGS. 19(b)-(n) illustrate a process flow for fabricating a micro-devicefor trapping, sorting, probing, measuring, treating, or modifying abiological subject (e.g., a single cell, a DNA or RNA molecule). A firstmaterial 1902 (e.g., a piezoelectric conducting material) and a secondmaterial 1903 (e.g., a conducting material) are sequentially depositedon a substrate 1901 (see FIGS. 19(b) and 19(c)). The second material1903 is subsequently patterned by lithography and etch processes (seeFIG. 19(d)). A third material 1904 is next deposited (as shown in FIG.19(e)) and planarized (see FIG. 19(f)). A layer of a fourth material1905 is subsequently deposited (see FIG. 19(g)) and patterned as a hardmask (see FIG. 19(h)), followed by etch to remove the third and firstmaterials from desired areas, which stops on the substrate 1901. FIG.19(i) is a perspective illustration of the device, while FIG. 19(j) is avertical illustration of the same device.

FIG. 19(k) illustrates the use of a micro-device capable of trapping aDNA 1920 and measuring various properties (e.g., electrical, magnetic,physical, thermal, chemical, biological, bio-chemical, or opticalproperties) of a DNA. Each probe tip 1912 matches up spatially witheither a major groove or minor groove of a double helix DNA. Meanwhile,two probes (1911 and 1910) configured at the end of the trench can forceor measure signals to each strand end of the DNA's double helix. Theprobes can be made of a conducting material with optionally apiezoelectric support structure, which can stretch forward and backwardat a desired distance. All the probes are numbered, addressed, andcontrolled by a controlling circuitry.

FIG. 19(l) shows a simplified form of the device illustrated in FIG.19(k). In this device, probe tips match spatially with interlacedgrooves of a double helix DNA. The number of groove intervals betweenthe adjacent probes is variable. If required, either DNA can be moved(for example, by pulling by probes 1910 and 1911) or the probes can movealong the trench direction, mapping out properties in a full or partialDNA.

FIG. 20 illustrates an apparatus of this invention that is capable ofdetecting or measuring the surface charge of a biological subject 2010.It includes a channel, a pair of plates 2022, and a slit 2030 whichseparates the channel into a top channel 2041 and a bottom channel 2051.When a biological subject 2010 carrying a surface charge (positivecharge shown in FIG. 20(a)) passes through the channel, under theinfluence of the voltage applied on the plates 2022 (with positivevoltage at the top plate and negative at the bottom plate), it will movetowards the bottom plate as shown in FIG. 20(b). Thus, the biologicalsubject 2010 will pass through the bottom channel 2051 when it reachesslit 2030. (If the biological subject 2010 carries a negative charge, itwould pass through the top channel 2041.) This way, a biological subjectwith unknown charge type (negative or positive) can be determined byusing this apparatus.

This device comprises at least 2 parts of channel, one of which ischannel 2060 where the biological subject is charged or modified, andthe other comprises at least one plate or slit to separate thebiological subjects (e.g., where the biological subjects are separated).

As surface charge will affect the shape of a biological subject, byusing novel and multiple plates, information on the shape and chargedistribution of biological subjects can be obtained. The generalprinciple and design of the micro-device can be extended to a broaderscope, thereby making it possible to obtain other information on thebiological subject via separation by applying other parameters such asion gradient, thermal gradient, optical beam, or another form of energy.

FIG. 21 illustrates another apparatus of this invention for detecting ormeasuring microscopic properties of a biological subject 2110 byutilizing a micro-device that includes a channel, a set of probes 2120,and a set of optical sensors 2132 (see, FIG. 21(a)). The detectedsignals by probes 2120 can be correlated to information including imagescollected by the optical sensors 2132 to enhance detection sensitivityand specificity. The optical sensors can be, e.g., a CCD camera, aflorescence light detector, a CMOS imaging sensor, or any combination.

Alternatively, a probe 2120 can be designed to trigger optical emissionsuch as florescence light emission 2143 in the targeted biologicalsubject such as tumor cells, which can then be detected by an opticalprobe 2132 as illustrated in FIG. 21(c). Specifically, biologicalsubjects can be first treated with a tag solution which can selectivelyreact to a tumor cell. Subsequently, upon reacting (contact ornon-contact) with probe 2120, optical emissions from the tumor celloccur and can be detected by optical sensors 2132. This novel processusing the micro-devices of this invention is more sensitive than suchconventional methods as traditional florescence spectroscopy as theemission trigger point is directly next to the optical probe and thetriggered signal 2143 can be recorded in real time and on-site, withminimum loss of signal.

FIG. 22 illustrates another embodiment of the apparatus of thisinvention, which can be used to separate biological subjects ofdifferent geometric size and detect their properties respectively. Itincludes at least an entrance channel 2210, a disturbing fluid channel2220, an accelerating chamber 2230, and two selecting channels 2240 and2250. The angle between 2220 and 2210 is between 0° and 180°. Thebiological subject 2201 flows in the x-direction from 2210 to 2230. Thebiocompatible distribution fluid 2202 flows from 2220 to 2230. Then thefluid 2202 will accelerate 2201 in y-direction. However, theacceleration correlates with the radius of the biological subjects andthe larger ones are less accelerated than the small ones. Thus, thelarger and smaller subjects are separated into different channels.Meanwhile, probes can be optionally assembled aside the sidewall of2210, 2220, 2230, 2240, and 2250. They could detect electric, magnetic,electromagnetic, thermal, optical, acoustical, biological, chemical,physical, or mechanical properties at the microscopic level.

The channel included in the apparatus of this invention can have a widthof, e.g., from 1 nm to 1 mm. The apparatus should have at least oneinlet channel and at least two outlet channels.

FIG. 23 shows another apparatus of this invention with an acousticdetector 2320 for measuring the acoustic property of a biologicalsubject 2301. This apparatus includes a channel 2310, and at least anultrasonic emitter and an ultrasonic receiver installed along thesidewall of the channel. When the biological subject 2301 passes throughthe channel 2310, the ultrasonic signal emitted from 2320 will bereceived after carrying information on 2301 by the receiver 2330. Thefrequency of the ultrasonic signal can be, e.g., from 2 MHz to 10 GHz,and the trench width of the channel can be, e.g., from 1 nm to 1 mm. Theacoustic transducer (i.e., the ultrasonic emitter) can be fabricatedusing a piezoelectric material (e.g., quartz, berlinite, gallium,orthophosphate, GaPO₄, tourmalines, ceramics, barium, titanate, BatiO₃,lead zirconate, titanate PZT, zinc oxide, aluminum nitride, andpolyvinylidene fluorides).

FIG. 24 shows another apparatus of this invention that includes apressure detector for biological subject 2401. It includes at least onechannel 2410 and whereon at least one piezoelectric detector 2420. Whenthe biologic subject 2401 passes through the channel, the piezoelectricdetector 2420 will detect the pressure of 2401, transform theinformation into an electrical signal, and send it out to a signalreader. Likewise, the trench width in the apparatus can be, e.g., from 1nm to 1 mm, and the piezoelectric material can be, e.g., quartz,berlinite, gallium, orthoposphate, GaPO₄, tourmalines, ceramics, barium,titanate, BatiO₃, lead zirconate, titanate PZT, zinc oxide, aluminumnitride, or polyvinylidene fluorides.

FIG. 25 shows another apparatus of this invention that include a concavegroove 2530 between a probe couple, in the bottom or ceiling of thechannel. When a biological subject 2510 passes through, the concave 2530can selectively trap the biological subject with particular geometriccharacteristics and makes the probing more efficiently. The shape ofconcave's projection can be rectangle, polygon, ellipse, or circle. Theprobe could detect electric, magnetic, electromagnetic, thermal,optical, acoustical, biological, chemical, physical, or mechanicalproperties. Similarly, the trench width can be, e.g., from 1 nm to 1 mm.FIG. 25(a) is an up-down view of this apparatus, FIG. 25(b) is a sideview, whereas FIG. 25(c) is a perspective view.

FIG. 26 is another apparatus of this invention that also includesconcave grooves 2630 (of a different shape from those shown in FIG. 25)on the bottom or ceiling of the channel. When a biological subject 2610passes through, the concave grooves 2630 will generate a turbulentfluidic flow, which can selectively trap the micro-biological objectswith particular geometric characteristics. The probe could detectelectric, magnetic, electromagnetic, thermal, optical, acoustical,biological, chemical, physical, or mechanical properties. The concavegroove is a cubic space or an angled space. The depth of the concavegroove can be, e.g., from 10 nm to 1 mm, and the channel width can be,e.g., from 1 nm to 1 mm.

FIG. 27 illustrated an apparatus of this invention with a steppedchannel 2710. When a biological subject 2701 passes through the channel2710, probe couples of different distances can be used to measuredifferent microscopic properties, or even the same microscopic atdifferent sensitivity at various steps (2720, 2730, 2740) with probeaside each step. This mechanism can be used in the phase lock-inapplication so that signal for the same microscopic property can beaccumulated. The probes can detect or measure microscopic electric,magnetic, electromagnetic, thermal, optical, acoustical, biological,chemical, physical, or mechanical properties.

FIG. 28 illustrates another apparatus of this invention with thermalmeters 2830. It includes a channel, a set of probes 2820, and a set ofthermal meters 2830. The thermal meters 2830 can be an infrared sensor,a transistor sub-threshold leakage current tester, or thermister.

FIG. 29 illustrates a specific apparatus of this invention whichincludes carbon a nano-tube 2920 with a channel 2910 inside, probes 2940which can detect microscopic electric, magnetic, electromagnetic,thermal, optical, acoustical, biological, chemical, physical, ormechanical properties. The carbon nano-tube 2920 as shown contains adouble-helix DNA molecule 2930. The carbon nano-tube can force and senseelectrical signals by the probes 2940 aside. The diameter of the carbonnano tube diameter can be, e.g., from 0.5 nm to 50 nm, and its lengthcan range from, e.g., 5 nm to 10 mm

FIG. 30 shows an integrated apparatus of this invention that includes adetecting device (shown in FIG. 30(a)) and an optical sensor (shown inFIG. 30(b)) which can be, e.g., a CMOS image sensor (CIS), aCharge-Coupled Device (CCD), a florescence light detector, or anotherimage sensor. The detecting device comprises at least a probe and achannel, and the image device comprises at least 1 pixel. FIG. 30(c-1)and FIG. 30(c-2) illustrate the device with the detecting device andoptical sensor integrated. As illustrated in FIG. 30(d), when biologicalsubjects 3001, 3002, 3003 pass through, the probe 3010 in the channel3020, its electric, magnetic, electromagnetic, thermal, optical,acoustical, biological, chemical, physical, or mechanical property couldbe detected by the probe 3010 (see FIG. 30(e)), meanwhile its imagecould be synchronously recorded by the optical sensor (FIG. 30(f)). Boththe probed signal and image are combined together to provide a diagnosisand enhanced detection sensitivity and specificity. Such a detectingdevice and an optical sensing device can be designed in a system-on-chipor be packaged into one chip.

FIG. 31 shows an apparatus with a detecting micro-device (FIG. 31(a))and a logic circuitry (FIG. 31(b)). The detecting device comprises atleast a probe and a channel, and the logic circuitry comprises anaddressor, an amplifier, and a RAM. When a biological subject 3101passes through the channel, its property could be detected by the probe3130, and the signal can be addressed, analyzed, stored, processed, andplotted in real time. FIG. 31(c-1) and FIG. 31(c-2) illustrate thedevice with detecting device and Circuitry integrated. Similarly, thedetecting device and the integrated circuit can be designed in aSystem-on-Chip or be packaged into one chip.

FIG. 32 shows an apparatus of this invention that comprises a detectingdevice (FIG. 32(a)) and a filter (FIG. 32(b)). When a biological subject3201 passes through the device, a filtration is performed in the filter,and irrelevant objects can be removed. The remaining subjects' propertycan then be detected by the probe device (FIG. 31(a)). The filtrationbefore probing will enhance the precision of the device. The width ofthe channel can also range, e.g., from 1 nm to 1 mm.

FIG. 33 shows the geometric factors of DNA 3330 such as spacing in DNA'sminor groove (3310) have an impact on spatial distribution ofelectrostatic properties in the region, which in turn may impact localbiochemical or chemical reactions in the segment of this DNA. Byprobing, measuring, and modifying spatial properties of DNA (such as thespacing of minor groove) using the disclosed detector and probe 3320,one may detect properties such as defect of DNA, predictreaction/process at the segment of the DNA, and repair or manipulategeometric properties and therefore spatial distribution of electrostaticfield/charge, impacting biochemical or chemical reaction at the segmentof the DNA. For example, tip 3320 can be used to physically increasespacing of minor groove 3310.

FIG. 34 shows the fabrication process for a micro-device of thisinvention that has a flat cover atop of trench to form a channel. Thiswill eliminate the need for couple two trenches to form a channel, whichcan be tedious for requiring perfect alignment.

The cover can be transparent and allow observation with a microscope. Itcan comprise or be made of silicon, SiGe, SiO₂, or Al₂O₃.

While for the purposes of demonstration and illustration, the abovecited novel, detailed examples show how microelectronics ornano-fabrication techniques and associated process flows can be utilizedto fabricate highly sensitive, multi-functional, powerful, andminiaturized detection devices, the principle and general approaches ofemploying microelectronics and nano-fabrication technologies in thedesign and fabrication of high performance detection devices have beencontemplated and taught, which can and should be expanded to variouscombination of fabrication processes including but not limited to thinfilm deposition, patterning (lithography and etch), planarization(including chemical mechanical polishing), ion implantation, diffusion,cleaning, various materials, combination of processes and steps, andvarious process sequences and flows. For example, in alternativedetection device design and fabrication process flows, the number ofmaterials involved can be fewer than or exceed four materials (whichhave been utilized in the above example), and the number of processsteps can be fewer or more than those demonstrated process sequences,depending on specific needs and performance targets. For example, insome CTC detection applications, a fifth material such as abiomaterial-based thin film can be used to coat a metal detection tip toenhance contact between the detection tip and a biological entity beingmeasured, thereby improving measurement sensitivity.

Applications for the detection apparatus and methods of this inventioninclude detection of cancers (e.g., in their early stage). Since cancercell and normal cell differ in a number of ways including differences inpossible microscopic properties such as electrical potential, surfacecharge, density, adhesion, and pH, novel micro-devices disclosed hereinare capable of detecting these differences and therefore applicable forenhanced capability to detect cancer, particularly in their early stage.In addition micro-devices for measuring electrical potential andelectrical charge parameters, micro-devices capable of carrying outmechanical property measurements (e.g., density) can also be fabricatedand used as disclosed herein. In mechanical property measurement forearly stage cancer detection, the focus will be on the mechanicalproperties that likely differentiate circulating tumor cells from normalcells. As an example, one can differentiate circulating tumor cells fromnormal cells by using a detection apparatus of this invention that isintegrated with micro-devices capable of carrying out micro-indentationmeasurements.

FIG. 35 is a diagram of an apparatus of this invention for detecting adisease in a biological subject. This apparatus includes apre-processing unit, a probing and detecting unit, a signal processing,and a disposal processing unit.

FIG. 36 shows an example of a sample filtration sub-unit in thepre-processing unit, which can separate the cells with differentdimensions or sizes. This device comprises at least one entrance channel3610, one disturbing fluid channel 3620, one accelerating chamber 3630,and two selecting channels (3640 and 3650). The angle 3660 between 3620and 3610 ranges from 0° to 180°.

The biological subject 3601 flows in the x direction from the entrancechannel 3610 to the accelerating chamber 3630. A bio-compatible fluid3602 flows from disturbing fluid channel 3620 to the acceleratingchamber 3630, it then accelerates the biological subject 3601 in they-direction. The acceleration correlates with the radius of thebiological subject and the larger ones are less accelerated than thesmaller ones. Then, the larger and smaller subjects are separated intodifferent selecting channels. Meanwhile, probes can be optionallyassembled on the sidewalls of the channels 3610, 3620, 3630, 3640, and3650. The probes could detect, at the microscopic level, electric,magnetic, electromagnetic, thermal, optical, acoustical, biological,chemical, biochemical, electro-mechanical, electro-chemical,electro-chemical-mechanical, physical, or mechanical properties.

FIG. 37 is a diagram of another example of a sample filtration unit inthe apparatus of this invention. 3701 represents small cells, while 3702represents large cells. When a valve 3704 is open and another valve 3703is closed, biological subjects (3701 and 3702) flow towards exit A.Large cells that have larger size than the filtration hole are blockedagainst exit A, while small cells are flushed out through exit A. Theentrance valve 3704 and exit A valve 3707 are then closed, and abio-compatible fluid is injected through the fluid entrance valve 3706.The fluid carries big cells are flushed out from exit B. The largercells are then analyzed and detected in the detection part of theinvention.

FIG. 38 is a diagram of a pre-processing unit of an apparatus of thisinvention. This unit includes a sample filtration unit, a rechargingunit or system for recharging nutrient or gas into the biologicalsubject, a constant pressure delivery unit, and a sample pre-probingdisturbing unit.

FIG. 39 is a diagram of an information or signal processing unit of anapparatus of this invention. This unit includes an amplifier (such as alock-in amplifier) for amplifying the signal, an A/D converter, and amicro-computer (e.g., a device containing a computer chip or informationprocessing sub-device), a manipulator, a display, and networkconnections.

FIG. 40 shows the integration of multiple signals which results incancellation of noise and enhancement of signal/noise ratio. In thisfigure, a biological 4001 is tested by Probe 1 during Δt between t1 andt2, and by Probe 2 during Δt between t3 and t4. 4002 is 4001's testedsignal from Probe 1, and 4003 is from Probe 2. Signal 4004 is theintegration result from signal 4002 and 4003. The noise cancels out eachother in certain extent and results in an improved signal strength orsignal/noise ratio. The same principle can be applied to data collectedfrom more than more than 2 micro-devices or probing units.

The micro-devices described herein, as well as some of the detectionparameters and properties and processes described herein, have been usedfor tests on cancerous samples (e.g., liver cancer samples and breastcancer samples) and controls (i.e., noncancerous or normal samples).While these samples were not CTC samples, the tests nonetheless wererelevant to this invention and indicative of the invention claimedherein as they showed advantages and improvements (for example, improvedsignal sensitivity) in cancer detection which will be very beneficialfor CTC detections. Further, these tests have proved the concept ofenhancing cancer detection signals and efficiency which is veryapplicable to CTC. In one set of experiments, use of the micro-devicesand test parameters described herein resulted in enhanced measurementsignal compared to a currently known method based on genomic analysis.Specifically, even after diluting the original cancer cell samples byover 20 times, signals differentiating the cancer cells from the normalsample were still detected. By comparison, a recently reported genomicanalysis detected signal of a cancer sample that was diluted only about5 times. The tested micro-devices, associated testing parameters, cancerand normal cell properties, and testing methodologies described hereinhave all showed high degree of measurement sensitivity, reliability, andrepeatability.

Additional tests were carried out in the laboratory with themicro-devices described herein on certain cancerous tissue samples (withmultiple samples for each type of cancer) although the micro-devices canbe used for detection of other types of cancer or other types oftreatment. In the tests, healthy control samples were obtained fromanimals with no known cancer disease at the time of collection and nohistory of malignant disease. Both cancerous samples and healthy controlsamples were collected and cultured in the same type of culturesolution. The cultured samples were then mixed with a dilution bufferand diluted to the same concentration. The diluted samples weremaintained at the room temperature for different time intervals andprocessed within a maximum of 6 hours after being recovered. The dilutedsamples were tested at the room temperature (20—23 oC) and in thehumidity of 30%˜40%. The samples were tested with a micro-device of thisinvention under the same conditions and stimulated by the same pulsesignal.

The test results show that, in general, the control groups' tested(measured) values (i.e., measured values in relative units for thetesting parameter) were lower than the cancerous or diseased groups.Under the same stimulation (in terms of stimulation type and level) witha stimulating or probing signal applied by a probing unit of the testedmicro-devices, the difference shown in the measured values between thecontrol groups and the cancerous groups became much more significant,e.g., ranging from 1.5 times to almost 8 times in terms of level ofincrease in such difference, compared with that without simulation. Inother words, the cancerous groups' response to the stimulating signalwas much higher than that of the control groups. Thus, the testedmicro-devices have been proven to be able to significantly enhance therelative sensitivity and specificity in the detection and measurement ofdiseased cells, in comparison to the control or healthy cells.

Further, the test results show that in terms of the novel parameterutilized by the micro-device of this invention, the cancerous group andthe control group showed significantly different response. Suchdifference is significantly greater than the measurement noise. Therewas a large window to separate the control groups from the cancerousgroups, showing a high degree of sensitivity of the novel measurementmethod and apparatus.

Although specific embodiments of this invention have been illustratedherein, it will be appreciated by those skilled in the art that anymodifications and variations can be made without departing from thespirit of the invention. The examples and illustrations above are notintended to limit the scope of this invention. Any combination ofdetection apparatus, micro-devices, fabrication processes, flowsequence, and applications of this invention, along with any obvioustheir extension or analogs, are within the scope of this invention.Further, it is intended that this invention encompass any arrangement,which is calculated to achieve that same purpose, and all suchvariations and modifications as fall within the scope of the appendedclaims.

All publications referred to above are incorporated herein by referencein their entireties. All the features disclosed in this specification(including any accompanying claims, abstract and drawings) may bereplaced by alternative features serving the same, equivalent or similarpurpose, unless expressly stated otherwise. Thus, unless expresslystated otherwise, each feature disclosed is one example of a genericseries of equivalent or similar features.

Other Embodiments

It is to be understood that while the invention has been described inconjunction with the detailed description thereof and accompanyingfigures, the foregoing description and accompanying figures are onlyintended to illustrate, and not limit the scope of the invention, whichis defined by the scope of the appended claims. Other aspects,advantages, and modifications are within the scope of the followingclaims. All publications referenced herein are incorporated by referencein their entireties.

What is claimed is:
 1. A micro-device comprising a micro-trench, a probeembedded along side the trench's side walls or bottom floor, asupporting structure to move the probe, and a controlling circuitry,wherein the micro-device is capable of trapping, measuring, detecting,sorting, counting, analyzing, modifying, correcting, or communicatingcirculating tumor cells in a biological subject by measuring a propertyof the circulating tumor cells at microscopic level.
 2. The micro-deviceof claim 1, wherein the width of the micro-trench ranges from about 0.5nm to about 200 μm or from about 0.5 nm to about 50 μm, the depth of themicro-trench ranges from about 0.5 nm to about 200 μm or from about 0.5nm to about 50 μm, and the length of the micro-trench ranges from about1 nm to about 50 mm or from about 1 nm to about 10 mm.
 3. Themicro-device of claim 1, wherein the probe comprises a conductivematerial, optionally a bio-compatible coating, and, optionally aflexible supporting structure to extend or contract the probe.
 4. Themicro-device of claim 1, further comprising an array of trenches.
 5. Themicro-device of claim 1, wherein the biological entity is a bloodsample, a urine sample, a saliva sample, a tear sample, a sweat sample,or a lymph sample.
 6. The micro device of claim 1, wherein the probe isconnected to the controlling circuit, and capable of receiving andexecuting instructions from the controlling circuit.
 7. The micro deviceof claim 1, wherein the probe is able to move the biological entity. 8.The micro device of claim 7, wherein the probe comprises a flexiblesupporting structure to extend or contract the probe to move thebiological entity.
 9. The micro device of claim 1, wherein the propertyto be measured at the microscopic level is an electrical, magnetic,electromagnetic, thermal, optical, acoustical, biological, chemical,electro-mechanical, electro-chemical, electro-optical, electro-thermal,electro-chemical-mechanical, bio-chemical, bio-mechanical, bio-optical,bio-thermal, bio-physical, bio-electro-mechanical, bio-electro-chemical,bio-electro-optical, bio-electro-thermal, bio-mechanical-optical,bio-mechanical thermal, bio-thermal-optical,bio-electro-chemical-optical, bio-electro-mechanical-optical,bio-electro-thermal-optical, bio-electro-chemical-mechanical, physical,or mechanical property, or a combination thereof.
 10. The micro deviceof claim 9, wherein the electrical property is surface charge, surfacepotential, resting potential, electrical current, electrical fielddistribution, surface charge distribution, cell electronic properties,cell surface electronic properties, dynamic changes in electronicproperties, dynamic changes in cell electronic properties, dynamicchanges in cell surface electronic properties, dynamic changes insurface electronic properties, electronic properties of cell membranes,dynamic changes in electronic properties of membrane surface, dynamicchanges in electronic properties of cell membranes, electrical dipole,electrical quadruple, oscillation in electrical signal, electricalcurrent, capacitance, three-dimensional electrical or charge clouddistribution, electrical properties at telomere of DNA and chromosome,capacitance, or impedance; the thermal property is temperature orvibrational frequency; the optical property is optical absorption,optical transmission, optical reflection, optical-electrical property,brightness, or fluorescent emission; the radiation property is radiationemission, signal triggered by radioactive material, or informationprobed by radioactive material; the chemical property is pH value,chemical reaction, bio-chemical reaction, bio-electro-chemical reaction,reaction speed, reaction energy, speed of reaction, oxygenconcentration, oxygen consumption rate, ionic strength, catalyticbehavior, chemical additives to trigger enhanced signal response,bio-chemical additives to trigger enhanced signal response, biologicaladditives to trigger enhanced signal response, chemicals to enhancedetection sensitivity, bio-chemicals to enhance detection sensitivity,biological additives to enhance detection sensitivity, or bondingstrength; the physical property is density, shape, volume, or surfacearea; the biological property is surface shape, surface area, surfacecharge, surface biological property, surface chemical property, pH,electrolyte, ionic strength, resistivity, cell concentration, orbiological, electrical, physical or chemical property of solution; theacoustic property is frequency, speed of acoustic waves, acousticfrequency and intensity spectrum distribution, acoustic intensity,acoustical absorption, or acoustical resonance; the mechanical propertyis internal pressure, hardness, flow rate, viscosity, fluid mechanicalproperties, shear strength, elongation strength, fracture stress,adhesion, mechanical resonance frequency, elasticity, plasticity, orcompressibility.
 11. The micro-device of claim 1, wherein the tumorcells are from prostate cancer, lung cancer, colon cancer, breastcancer, brain cancer, cervical cancer, Hodgkin's lymphoma, non-Hodgkin'slymphoma, kidney cancer, leukemia, liver cancer, ovarian cancer, skincancer, testicular cancer, thyroid cancer, pancreatic cancer,endometrial cancer, esophageal cancer, or uterine cancer.